Orders of magnitude (length)

To help compare different orders of magnitude, the following list describes various lengths between ${\displaystyle 1.6\times 10^{-35}}$ metres and ${\displaystyle 10^{10^{10^{122}}}}$metres.

Astronomical scale

Factor (m)	Multiple	Value	Item
107	10 Mm	12.756 Mm	Equatorial diameter of Earth
		20.004 Mm	Length of a meridian on Earth (distance between Earth's poles along the surface)[36]
		40.075 Mm	Length of Earth's equator
108	100 Mm	142.984 Mm	Diameter of Jupiter
		299.792 Mm	Distance traveled by light in vacuum in one second (a light-second, exactly 299,792,458 m by definition of the speed of light)
		384.4 Mm	Moon's orbital distance from Earth
109	1 gigametre (Gm)	1.39 Gm	Diameter of the Sun
		5.15 Gm	Greatest mileage ever recorded by a car (3.2 million miles by a 1966 Volvo P-1800S)[37]
1010	10 Gm	18 Gm	Approximately one light-minute
1011	100 Gm	150 Gm	1 astronomical unit (au); mean distance between Earth and Sun
1012	1 terametre (Tm)	1.3 Tm	Optical diameter of Betelgeuse
		1.4 Tm	Orbital distance of Saturn from Sun
		2 Tm	Estimated optical diameter of VY Canis Majoris, one of the largest-known stars
		5.9 Tm	Orbital distance of Pluto from the Sun
		~ 7.5 Tm	Outer boundary of the Kuiper belt
1013	10 Tm		Diameter of the Solar System as a whole[1]
		21.49 Tm	Distance of the Voyager 1 spacecraft from Sun (as of Oct 2018), the farthest man-made object so far[38]
		62.03 Tm	Estimated radius of the event horizon of the supermassive black hole in NGC 4889, the largest-known black hole to date
1014	100 Tm	180 Tm	Size of the debris disk around the star 51 Pegasi[39]
		200 Tm	Total length of DNA molecules in all cells of an adult human body
1015	1 petametre (Pm)	~7.5 Pm	Supposed outer boundary of the Oort cloud (~ 50,000 au)
		9.461 Pm	Distance traveled by light in vacuum in one year; at its current speed, Voyager 1 would need 17,500 years to travel this distance
1016	10 Pm	30.857 Pm	1 parsec
		39.9 Pm	Distance to nearest star (Proxima Centauri)
		41.3 Pm	As of March 2013, distance to nearest discovered extrasolar planet (Alpha Centauri Bc)
1017	100 Pm	193 Pm	As of October 2010, distance to nearest discovered extrasolar planet with potential to support life as presently defined by science (Gliese 581 d)
		615 Pm	Approximate radius of humanity's radio bubble, caused by high-power TV broadcasts leaking through the atmosphere into outer space
1018	1 exametre (Em)	1.9 Em	Distance to nearby solar twin (HIP 56948), a star with properties virtually identical to the Sun[40]
1019	10 Em	9.46 Em	Average thickness of Milky Way Galaxy[41] (1,000 to 3,000 ly by 21 cm observations[42])
1020	100 Em	113.5 Em	Thickness of Milky Way Galaxy's gaseous disk[43]
1021	1 zettametre (Zm)
		1.54 Zm	Distance to SN 1987A, the most recent naked eye supernova
		1.62 Zm	Distance to the Large Magellanic Cloud (a dwarf galaxy orbiting the Milky Way)
		1.66 Zm	Distance to the Small Magellanic Cloud (another dwarf galaxy orbiting the Milky Way)
		1.9 Zm	Diameter of galactic disk of Milky Way Galaxy[44][45][46][47]
		6.15 Zm	Diameter of the low surface brightness disc halo of the giant spiral galaxy Malin 1
1022	10 Zm	13.25 Zm	Radius of the diffuse stellar halo of IC 1101, one of the largest-known galaxies
		24 Zm	Distance to Andromeda Galaxy
		30.857 Zm	1 megaparsec
		50 Zm	Diameter of Local Group of galaxies
1023	100 Zm	300–600 Zm	Distance to Virgo cluster of galaxies
1024	1 yottametre (Ym)	2.19 Ym	Diameter of the Local Supercluster and the largest voids and filaments
		2.8 Ym	End of Greatness
		~5 Ym	Diameter of the Horologium Supercluster[48]
		9.461 Ym	Diameter of the Pisces–Cetus Supercluster Complex, the supercluster complex which includes Earth
1025	10 Ym	13 Ym	Length of the Sloan Great Wall, a giant wall of galaxies (galactic filament)[49]
		30.857 Ym	1 gigaparsec
		37.84 Ym	Length of the Huge-LQG, a group of 73 quasars
1026	100 Ym	95 Ym	Estimated light travel distance to certain quasars. Length of the Hercules–Corona Borealis Great Wall, a colossal wall of galaxies, the largest and the most massive structure in the observable universe as of 2014
		127 Ym	Estimated light travel distance to GN-z11, the most distant object ever observed
		870 Ym	Approximate diameter (comoving distance) of the visible universe[1]
1027	1 Rm	1.2 Rm	Lower bound of the (possibly infinite) radius of the universe, if it is a 3-sphere, according to one estimate using the WMAP data at 95% confidence[50] It equivalently implies that there are at minimum 21 particle horizon-sized volumes in the universe.
${\displaystyle 10^{10^{115}}}$[note 3]	${\displaystyle 10^{10^{115}}}$ m	${\displaystyle 10^{10^{115}}}$ m	According to the laws of probability, the distance one must travel until one encounters a volume of space identical to our observable universe with conditions identical to our own.[51][52]
${\displaystyle 10^{10^{10^{122}}}}$	${\displaystyle 10^{10^{10^{122}}}}$ m	${\displaystyle 10^{10^{10^{122}}}}$ m	Minimal size of universe after cosmological inflation, implied by one resolution of the No-Boundary Proposal[53]

The quectometre (SI symbol: qm) is a unit of length in the metric system equal to 10⁻³⁰ metres. To help compare different orders of magnitude, this section lists lengths shorter than 10⁻³⁰ m (1 qm).

• 1.6 × 10⁻⁵ quectometres (1.6 × 10⁻³⁵ metres) – the Planck length (Measures of distance shorter than this do not make physical sense, according to current theories of physics.)
• 1 qm – 1 quectometre, the smallest named subdivision of the metre in the SI base unit of length, one nonillionth of a metre.[54]

The rontometre (SI symbol: rm) is a unit of length in the metric system equal to 10⁻²⁷ metres.

• 1 rm – 1 rontometre, a subdivision of the metre in the SI base unit of length, one octillionth of a metre.[54]

• 10 rm – the length of one side of a square whose area is one shed, a unit of target cross section used in nuclear physics

The yoctometre (SI symbol: ym) is a unit of length in the metric system equal to 10⁻²⁴ metres.

• 2 ym – the effective cross-section radius of 1 MeV neutrinos as measured by Clyde Cowan and Frederick Reines

The zeptometre (SI symbol: zm) is a unit of length in the metric system equal to 10⁻²¹ metres. To help compare different orders of magnitude, this section lists lengths between 10⁻²¹ m and 10⁻²⁰ m (1 zm and 10 zm).

• 2 zm – the upper bound for the width of a cosmic string in string theory.
• 2 zm – radius of effective cross section for a 20 GeV neutrino scattering off a nucleon
• 7 zm – radius of effective cross section for a 250 GeV neutrino scattering off a nucleon

To help compare different orders of magnitude, this section lists lengths between 10⁻²⁰ m and 10⁻¹⁹ m (10 zm and 100 zm).

To help compare different orders of magnitude, this section lists lengths between 10⁻¹⁹ m and 10⁻¹⁸ m (100 zm and 1 am).

• 177 zm – de Broglie wavelength of protons at the Large Hadron Collider (7 TeV as of 2010)

The attometre (SI symbol: am) is a unit of length in the metric system equal to 10⁻¹⁸ metres. To help compare different orders of magnitude, this section lists lengths between 10⁻¹⁸ m and 10⁻¹⁷ m (1 am and 10 am).

• 1 am – sensitivity of the LIGO detector for gravitational waves
• 1 am – upper limit for the size of quarks and electrons

To help compare different orders of magnitude, this section lists lengths between 10⁻¹⁷ m and 10⁻¹⁶ m (10 am and 100 am).

• 10 am – range of the weak force

• 86 am – Charge radius of a Bottom eta meson[55]

To help compare different orders of magnitude, this section lists lengths between 10⁻¹⁶ m and 10⁻¹⁵ m (100 am and 1 fm).

• 850 am – approximate proton radius

The femtometre (SI symbol: fm) is a unit of length in the metric system equal to 10⁻¹⁵ metres. In particle physics, this unit is sometimes called a fermi, also with abbreviation "fm". To help compare different orders of magnitude, this section lists lengths between 10⁻¹⁵ metres and 10⁻¹⁴ metres (1 femtometre and 10 fm).

• 1 fm – diameter of a neutron, approximate range-limit of the color force carried between quarks by gluons[6][7]
• 1.5 fm – diameter of the scattering cross section of an 11 MeV proton with a target proton
• 1.75 fm – the effective charge diameter of a proton[56]
• 2.81794 fm – classical electron radius
• 3 fm – approximate range-limit of the nuclear binding force mediated by mesons[6][7]
• 7 fm – the radius of the effective scattering cross section for a gold nucleus scattering a 6 MeV alpha particle over 140 degrees

To help compare different orders of magnitude, this section lists lengths between 10⁻¹⁴ m and 10⁻¹³ m (10 fm and 100 fm).

• 1.75 to 15 fm – Diameter range of the atomic nucleus
• 10 fm – the length of one side of a square whose area is one barn (10^-28 m²), a unit of target cross section used in nuclear physics
• 30.8568 fm – 1 quectoparsec (10⁻³⁰ parsecs)

To help compare different orders of magnitude, this section lists lengths between 10⁻¹³ m and 10⁻¹² m (100 fm and 1 pm).

• 570 fm – typical distance from the atomic nucleus of the two innermost electrons (electrons in the 1s shell) in the uranium atom, the heaviest naturally-occurring atom

The picometre (SI symbol: pm) is a unit of length in the metric system equal to 10⁻¹² metres (1/1000000000000 m = 0.000000000001 m). To help compare different orders of magnitude this section lists lengths between 10⁻¹² and 10⁻¹¹ m (1 pm and 10 pm).

• 1 pm – distance between atomic nuclei in a white dwarf
• 1 pm – reference value of particle displacement in acoustics[57]
• 2.4 pm – The Compton wavelength of an electron
• 5 pm – shorter X-ray wavelengths (approx.)

To help compare different orders of magnitude this section lists lengths between 10⁻¹¹ and 10⁻¹⁰ m (10 pm and 100 pm).

• 25 pm – approximate radius of a helium atom, the smallest neutral atom
• 30.8568 pm – 1 rontoparsec
• 50 pm – radius of a hydrogen atom
• 50 pm – bohr radius: approximate radius of a hydrogen atom
• ~50 pm – best resolution of a high-resolution transmission electron microscope
• 60 pm – radius of a carbon atom
• 93 pm – length of a diatomic carbon molecule
• 96 pm – H–O bond length in a water molecule

To help compare different orders of magnitude this section lists lengths between 10⁻¹⁰ and 10⁻⁹ m (100 pm and 1 nm; 1 Å and 10 Å).

• 100 pm – 1 ångström
• 100 pm – covalent radius of sulfur atom
• 120 pm – van der Waals radius of a neutral hydrogen atom
• 120 pm – radius of a gold atom
• 126 pm – covalent radius of ruthenium atom
• 135 pm – covalent radius of technetium atom
• 150 pm – Length of a typical covalent bond (C–C)
• 153 pm – covalent radius of silver atom
• 155 pm – covalent radius of zirconium atom
• 175 pm – covalent radius of thulium atom
• 200 pm – highest resolution of a typical electron microscope
• 225 pm – covalent radius of caesium atom
• 280 pm – Average size of the water molecule
• 298 pm – radius of a caesium atom, calculated to be the largest atomic radius
• 340 pm – thickness of single layer graphene
• 356.68 pm – width of diamond unit cell
• 403 pm – width of lithium fluoride unit cell
• 500 pm – Width of protein α helix
• 543 pm – silicon lattice spacing
• 560 pm – width of sodium chloride unit cell
• 700 pm – width of glucose molecule
• 700 pm – diameter of a buckyball[58]
• 780 pm – mean width of quartz unit cell
• 820 pm – mean width of ice unit cell
• 900 pm – mean width of coesite unit cell

The nanometre (SI symbol: nm) is a unit of length in the metric system equal to 10⁻⁹ metres (1/1000000000 m = 0.000000001 m). To help compare different orders of magnitude, this section lists lengths between 10⁻⁹ and 10⁻⁸ m (1 nm and 10 nm).

• 1 nm – diameter of a carbon nanotube
• 1 nm – roughly the length of a sucrose molecule, calculated by Albert Einstein
• 2.3 nm – length of a phospholipid
• 2.3 nm – smallest gate oxide thickness in microprocessors
• 3 nm – width of a DNA helix
• 3 nm – flying height of the head of a hard disk
• 3 nm – as of 2019, the average half-pitch of a memory cell expected to be manufactured circa 2022
• 3.4 nm – length of a DNA turn (10 bp)
• 3.8 nm – size of an albumin molecule
• 5 nm – size of the gate length of a 16 nm processor
• 5 nm – as of October 2018, the average half-pitch of a memory cell manufactured circa 2019–2020
• 6 nm – length of a phospholipid bilayer
• 6–10 nm – thickness of cell membrane
• 6.8 nm – width of a haemoglobin molecule
• 7 nm – diameter of actin filaments
• 7 nm – the average half-pitch of a memory cell manufactured circa 2018
• 10 nm – Thickness of cell wall in Gram-negative bacteria

To help compare different orders of magnitude this section lists lengths between 10⁻⁸ and 10⁻⁷ m (10 nm and 100 nm).

• 10 nm – the average length of a nanowire
• 10 nm – lower size of tobacco smoke[59]
• 10 nm – the average half-pitch of a memory cell manufactured circa 2016 –2017
• 13 nm – the length of the wavelength that is used for EUV lithography
• 14 nm – Length of a porcine circovirus
• 14 nm – the average half-pitch of a memory cell manufactured circa 2013
• 15 nm – Length of an antibody
• 18 nm – diameter of tobacco mosaic virus[60] (Generally, viruses range in size from 20 nm to 450 nm.)
• 20 nm – Length of a nanobe, could be one of the smallest forms of life
• 20–80 nm – thickness of cell wall in Gram-positive bacteria[61]
• 20 nm – thickness of bacterial flagellum
• 22 nm – the average half-pitch of a memory cell manufactured circa 2011–2012
• 22 nm – Smallest feature size of production microprocessors in September 2009[62]
• 25 nm – diameter of a microtubule
• 30 nm – lower size of cooking oil smoke
• 30.8568 nm – 1 yoctoparsec
• 32 nm – the average half-pitch of a memory cell manufactured circa 2009–2010
• 40 nm – extreme ultraviolet wavelength
• 45 nm – the average half-pitch of a memory cell manufactured circa 2007–2008
• 50 nm – upper size for airborne virus particles
• 50 nm – flying height of the head of a hard disk[63]
• 65 nm – the average half-pitch of a memory cell manufactured circa 2005–2006
• 58 nm – height of a T7 bacteriophage
• 90 nm – Human immunodeficiency virus (HIV) (generally, viruses range in size from 20 nm to 450 nm)
• 90 nm – the average half-pitch of a memory cell manufactured circa 2002–2003
• 100 nm – Length of a mesoporous silica nanoparticle

Comparison of sizes of semiconductor manufacturing process nodes with some microscopic objects and visible light wavelengths. At this scale, the width of a human hair is about 10 times that of the image.[64]

To help compare different orders of magnitude, this section lists lengths between 10⁻⁷ and 10⁻⁶ m (100 nm and 1 μm).

• 100 nm – greatest particle size that can fit through a surgical mask[65]
• 100 nm – 90% of particles in wood smoke are smaller than this.
• 120 nm – greatest particle size that can fit through a ULPA filter
• 120 nm – diameter of a human immunodeficiency virus (HIV)[66]
• 120 nm – approximate diameter of SARS-CoV-2[67]
• 125 nm – standard depth of pits on compact discs (width: 500 nm, length: 850 nm to 3.5 μm)
• 180 nm – typical length of the rabies virus
• 200 nm – typical size of a Mycoplasma bacterium, among the smallest bacteria
• 300–400 nm – near ultraviolet wavelength
• 300 nm – greatest particle size that can fit through a HEPA (high efficiency particulate air) filter (N100 removes up to 99.97% at 0.3 micrometres, N95 removes up to 95% at 0.3 micrometres)
• 400–420 nm – wavelength of violet light (see Color and Visible spectrum)
• 420–440 nm – wavelength of indigo light
• 440–500 nm – wavelength of blue light
• 500–520 nm – wavelength of cyan light
• 520–565 nm – wavelength of green light
• 565–590 nm – wavelength of yellow light
• 590–625 nm – wavelength of orange light
• 625–700 nm – wavelength of red light
• 700–1.4 μm – wavelength of near-infrared radiation

The silk for a spider's web is 5–7 μm (0.00020–0.00028 in) wide

The micrometre (SI symbol: μm) is a unit of length in the metric system equal to 10⁻⁶ metres (1/1000000 m = 0.000001 m). To help compare different orders of magnitude, this section lists some items with lengths between 10⁻⁶ and 10⁻⁵ m (between 1 and 10 micrometres, or μm).

• ~0.7–300 μm – wavelength of infrared radiation
• 1 μm – the side of a square of area 10⁻¹² m²
• 1 μm – edge of cube of volume 10⁻¹⁸ m³ (1 fL)
• 1–10 μm – diameter of a typical bacterium
• 1 μm – length of a lysosome
• 1–2 μm – anthrax spore[68]
• 2 μm – length of an average E. coli bacteria
• 3–4 μm – size of a typical yeast cell[69]
• 5 μm – length of a typical human spermatozoon's head[70]
• 6 μm – thickness of the tape in a 120-minute (C120) compact cassette[71]
• 7 μm – diameter of the nucleus of a typical eukaryotic cell
• about 7 μm – diameter of human red blood cells[72]
• 3–8 μm – width of strand of spider web silk[73]
• 5–10 μm – width of a chloroplast[74]
• 8–11 μm – size of a ground-level fog or mist droplet[75][note 4]
• 7–12 μm – the diameter of human white blood cells
• 8–10 μm – the diameter of human macrophages

Fog particles are around 10–50 μm (0.00039–0.00197 in) long.

To help compare different orders of magnitude, this section lists lengths between 10⁻⁵ m and 10⁻⁴ m (10 μm and 100 μm).

• 10 μm – width of cotton fibre[76]
• 10 μm – tolerance of a Lego brick[77]
• 10 μm – transistor width of the Intel 4004, the world's first commercial microprocessor
• 10 μm – mean longest dimension of a human red blood cell
• 5–20 μm – dust mite excreta[78]
• 10.6 μm – wavelength of light emitted by a carbon dioxide laser
• 15 μm – width of silk fibre
• 17 μm – minimum width of a strand of human hair[24]
• 17.6 μm – one twip, a unit of length in typography
• 10 to 55 μm – width of wool fibre[76]
• 25.4 μm – 1/1,000 inch, commonly referred to as 1 mil in the U.S. and 1 thou in the UK
• 30 μm – length of a human skin cell
• 30.8568 μm – 1 zeptoparsec
• 50 μm – typical length of Euglena gracilis, a flagellate protist
• 50 μm – typical length of a human liver cell, an average-sized body cell
• 50 μm – length of a silt particle
• 60 μm – length of a sperm cell
• 70 to 180 μm – thickness of paper

A paramecium is around 300 μm (0.012 in) long.

To help compare different orders of magnitude, this section lists lengths between 10⁻⁴ m and 10⁻³ m (100 μm and 1 mm). The term myriometre (abbr. mom, equivalent to 100 micrometres; frequently confused with the myriametre, 10 kilometres)[79] is deprecated; the decimal metric prefix myrio-[80] is obsolete[81][82][83] and was not included among the prefixes when the International System of Units was introduced in 1960.

• 100 μm – 1/10 of a millimetre
• 100 μm – 0.00394 inches
• 100 μm – smallest distance that can be seen with the naked eye
• 100 μm – average diameter of a strand of human hair[24]
• 100 μm – thickness of a coat of paint
• 100 μm – length of a dust particle
• 120 μm – the geometric mean of the Planck length and the diameter of the observable universe: √8.8 × 10²⁶ m × 1.6 × 10⁻³⁵ m
• 120 μm – diameter of a human ovum
• 170 μm – length of the largest sperm cell in nature, belonging to the Drosophila bifurca fruit fly[84][85]
• 181 μm – maximum width of a strand of human hair[24]
• 100–400 μm – length of Demodex mites living in human hair follicles
• 175–200 μm – typical thickness of a solar cell.
• 200 μm – typical length of Paramecium caudatum, a ciliate protist
• 200 μm – nominal width of the smallest commonly available mechanical pencil lead (0.2 mm)
• 250–300 μm – length of a dust mite[86]
• 340 μm – length of a pixel on a 17-inch monitor with a resolution of 1024×768
• 500 μm – typical length of Amoeba proteus, an amoeboid protist
• 500 μm – MEMSs micro-engine
• 500 μm – average length of a grain of sand
• 500 μm – average length of a grain of salt
• 500 μm – average length of a grain of sugar
• 560 μm – thickness of the central area of a human cornea[25]
• 750 μm – diameter of a Thiomargarita namibiensis, the largest bacteria known[87]
• 760 μm – thickness of an identification card

An average red ant is about 5 mm (0.20 in) long.

The millimetre (SI symbol: mm) is a unit of length in the metric system equal to 10⁻³ metres (1/1000 m = 0.001 m). To help compare different orders of magnitude, this section lists lengths between 10⁻³ m and 10⁻² m (1 mm and 1 cm).

• 1.0 mm – 1/1,000 of a metre
• 1.0 mm – 0.03937 inches or 5/127 (exactly)
• 1.0 mm – side of a square of area 1 mm²
• 1.0 mm – diameter of a pinhead
• 1.5 mm – average length of a flea[26]
• 2.54 mm – distance between pins on old dual in-line package (DIP) electronic components
• 5 mm – length of an average red ant
• 5 mm – diameter of an average grain of rice
• 5.56×45mm NATO – standard ammunition size
• 6 mm – approximate width of a pencil
• 7 mm – length of a Paedophryne amauensis, the smallest-known vertebrate[88]
• 7.1 mm – length of a sunflower seed
• 7.62×51mm NATO – common military ammunition size[89]
• 8 mm – width of old-format home movie film
• 8 mm – length of a Paedocypris progenetica, the smallest-known fish[90]

An average human fingernail is 1 cm (0.39 in) wide

The centimetre (SI symbol: cm) is a unit of length in the metric system equal to 10⁻² metres (1/100 m = 0.01 m). To help compare different orders of magnitude, this section lists lengths between 10⁻² m and 10⁻¹ m (1 cm and 1 dm).

• 1 cm – 10 millimetres
• 1 cm – 0.39 inches
• 1 cm – edge of a square of area 1 cm²
• 1 cm – edge of a cube of volume 1 mL
• 1 cm – length of a coffee bean
• 1 cm – approximate width of average fingernail
• 1.2 cm – length of a bee
• 1.2 cm – diameter of a die
• 1.5 cm – length of a very large mosquito
• 1.6 cm – length of a Jaragua Sphaero, a very small reptile
• 1.7 cm – length of a Thorius arboreus, the smallest salamander[91]
• 2 cm – approximate width of an adult human finger
• 2.54 cm – 1 inch
• 3.08568 cm – 1 attoparsec
• 3.4 cm – length of a quail egg[92]
• 3.5 cm – width of film commonly used in motion pictures and still photography
• 3.78 cm – amount of distance the Moon moves away from Earth each year[93]
• 4.3 cm – minimum diameter of a golf ball[94]
• 5 cm – usual diameter of a chicken egg
• 5 cm – height of a hummingbird, the smallest-known bird
• 5.08 cm – 2 inches,
• 5.5 × 5.5 × 5.5 cm – dimensions of a 3x3x3 Rubik's cube
• 6.1 cm – average height of an apple
• 7.3–7.5 cm – diameter of a baseball[27]
• 8.6 cm × 5.4 cm – dimensions of a standard credit card
• 9 cm – length of a speckled padloper, the smallest-known turtle

An adult human foot is about 28 cm (11 in) long.

The decimetre (SI symbol: dm) is a unit of length in the metric system equal to 10⁻¹ metres (1/10 m = 0.1 m). To help compare different orders of magnitude, this section lists lengths between 10 centimetres and 100 centimetres (10⁻¹ metre and 1 metre).

Leonardo da Vinci drew the Vitruvian Man within a square of side 1.83 m (6 ft 0 in) and a circle about 1.2 m (3 ft 11 in) in radius

To help compare different orders of magnitude, this section lists lengths between one metre and ten metres. Light, in vacuum, travels 1 metre in 1⁄299,792,458, or 3.3356409519815E-9 of a second.

A blue whale has been measured as 33 m (108 ft) long; this drawing compares its length to that of a human diver and a dolphin.

The decametre (SI symbol: dam) is a unit of length in the metric system equal to 10 metres (10¹ m). To help compare different orders of magnitude, this section lists lengths between 10 and 100 metres.

The Great Pyramid of Giza is 138.8 m (455 ft) high.

British driver location sign and location marker post on the M27 in Hampshire. The location marker posts are installed at 100-metre intervals.[108]

The hectometre (SI symbol: hm) is a unit of length in the metric system equal to 100 metres (10² m). To compare different orders of magnitude this section lists lengths between 100 metres and 1,000 metres (1 kilometre).

Mount Fuji is 3.776 kilometres (2.346 mi) high.

The kilometre (SI symbol: km) is a unit of length in the metric system equal to 1000 metres (10³ m). To help compare different orders of magnitude, this section lists lengths between 1 kilometre and 10 kilometres (10³ and 10⁴ metres).

The Strait of Gibraltar is 13 km (8.1 mi) wide.

To help compare different orders of magnitude, this section lists lengths between 10 and 100 kilometres (10⁴ to 10⁵ metres). The myriametre[125] (sometimes also spelled myriometre; 10,000 metres) is a deprecated unit name; the decimal metric prefix myria-[80] (sometimes also written as myrio-[126][127][128]) is obsolete[81][82][83] and not included among the prefixes when the International System of Units was introduced in 1960.

Conversions

10 kilometres is equal to:

Distance marker on the Rhine: 36 (XXXVI) myriametres from Basel. The stated distance is 360 km (220 mi); the comma is the decimal separator in Germany.

• 10,000 metres
• 6.2 miles
• 1 mil (the Scandinavian mile), now standardized as 10 km:
  • 1 mil, the unit of measure commonly used in Norway and Sweden[129] used to be 11,295 m in Norway and 10,688 m in Sweden.
• farsang, unit of measure commonly used in Iran and Turkey[130]

The Suez Canal is 163 km (101 mi) long.

A length of 100 kilometres (about 62 miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects. It is the altitude at which the FAI defines spaceflight to begin.

To help compare orders of magnitude, this section lists lengths between 100 and 1,000 kilometres (10⁵ and 10⁶ metres).

Small planets, the Moon and dwarf planets in the Solar System have diameters from one to ten million metres. Top row: Mars (left), Mercury (right); bottom row: Moon (left), Pluto (center), and Haumea (right), to scale.

The megametre (SI symbol: Mm) is a unit of length in the metric system equal to 1000000 metres (10⁶ m). To help compare different orders of magnitude, this section lists lengths starting at 10⁶ m (1 Mm or 1,000 km).

Planets from Venus up to Uranus have diameters from ten to one hundred million metres. Top row: Uranus (left), Neptune (right); middle row: Earth (left), Sirius B (center), and Venus (right), to scale

To help compare different orders of magnitude, this section lists lengths starting at 10⁷ metres (10 megametres or 10,000 kilometres).

The Earth-Moon orbit, Saturn, OGLE-TR-122b, Jupiter, and other objects, to scale. Click on image for detailed view and links to other length scales.

Scale model at megametres of the main Solar System bodies.

To help compare different orders of magnitude, this section lists lengths starting at 10⁸ metres (100 megametres or 100,000 kilometres or 62,150 miles).

• 102 Mm – Diameter of HD 149026 b, an unusually dense Jovian planet
• 115 Mm – Width of Saturn's Rings
• 120 Mm – Diameter of EBLM J0555-57Ab, the smallest-known star
• 120 Mm – Diameter of Saturn
• 142 Mm – Diameter of Jupiter, the largest planet in the Solar System
• 170 Mm – Diameter of TRAPPIST-1, a star recently discovered to have seven planets around it
• 174 Mm – Diameter of OGLE-TR-122b
• 180 Mm – Average distance covered during life
• 196 Mm – Diameter of Proxima Centauri, a typical red dwarf
• 257 Mm – Diameter of TrES-4 b
• 272 Mm – Diameter of WASP-12b
• 299.792 Mm – One light-second; the distance light travels in vacuum in one second (see speed of light)
• 300 Mm – Diameter of WASP-79b
• 314 Mm – Diameter of CT Cha b
• 384.4 Mm (238,855 mi) – Average Earth-Moon distance[145]
• 671 Mm – Separation between Jupiter and Europa
• 428 Mm – Diameter of GQ Lupi b, one of the largest-known planets
• 986 Mm – Diameter of HD 100546 b's surrounding disk

13 things in the gigametre group

Upper part: Gamma Orionis, Algol B, the Sun (centre), and other objects to scale

; lower part: their darker mirror images (artist's interpretation).

The gigametre (SI symbol: Gm) is a unit of length in the metric system equal to 1000000000 metres (10⁹ m). To help compare different distances this section lists lengths starting at 10⁹ metres (1 gigametre (Gm) or 1 billion metres).

• 1.2 Gm – Separation between Saturn and Titan
• 1.39 Gm – Diameter of Sun[146]
• 1.5 Gm – Orbit from Earth of the James Webb Space Telescope
• 1.71 Gm – Diameter of Alpha Centauri A, one of the closest stars.[147]
• 2.19 Gm – Closest approach of Comet Lexell to Earth, happened on 1 July 1770; closest comet approach on record
• 2.38 Gm – diameter of Sirius A, brightest naked eye star.[148]
• 3 Gm – Total length of "wiring" in the human brain[149]
• 3.5 Gm – Diameter of Vega[150]
• 4.2 Gm – Diameter of Algol B
• 5.0 Gm – Closest approach of Comet Halley to Earth, happened on 10 April 837
• 5.0 Gm – (proposed) Size of the arms of the giant triangle shaped Michelson interferometer of the Laser Interferometer Space Antenna (LISA) planned to start observations sometime in the 2030s.
• 7.9 Gm – Diameter of Gamma Orionis
• 9.0 Gm – Estimated diameter of the event horizon of Sagittarius A*, the supermassive black hole in the center of the Milky Way galaxy

Rigel and Aldebaran (top left and right) compared to smaller stars, the Sun (very small dot in lower middle, with orbit of Mercury as yellow ellipse) and transparent sphere with radius of one light-minute.

To help compare different distances this section lists lengths starting at 10¹⁰ metres (10 gigametres (Gm) or 10 million kilometres, or 0.07 astronomical units).

• 12.6 Gm – Diameter of Pollux, the closest red giant star to the Sun[151]
• 15 Gm – Closest distance of Comet Hyakutake from Earth
• 18 Gm – One light-minute (see yellow sphere in right-hand diagram)
• 24 Gm – Radius of a heliostationary orbit
• 30.8568 Gm – 1 microparsec
• ≈35 Gm – Radius of Aldebaran, a red giant star
• ≈35 Gm – Diameter of Arcturus, a close red giant star.[152]
• 46 Gm – Perihelion distance of Mercury (yellow ellipse on the right)
• 55 Gm – 60,000-year perigee of Mars (last achieved on 27 August 2003)
• 55 Gm – Radius of Rigel, a blue supergiant star (largest star on right)[153]
• 58 Gm – Average passing distance between Earth and Mars at the moment they overtake each other in their orbits
• 61 Gm[154] – Diameter of Aldebaran, a red giant star (large star on right)
• 70 Gm – Aphelion distance of Mercury
• 76 Gm – Neso's apocentric distance; greatest distance of a natural satellite from its parent planet (Neptune)

From largest to smallest: Jupiter's orbit, red supergiant star Betelgeuse, Mars' orbit, Earth's orbit, star R Doradus, and orbits of Venus, Mercury. Inside R Doradus's depiction are the blue supergiant star Rigel and red giant star Aldebaran. The faint yellow glow around the Sun represents one light-minute. Click image to see more details and links to their scales.

To help compare distances at different orders of magnitude this section lists lengths starting at 10¹¹ metres (100 gigametre or 100 million kilometres or 0.7 astronomical units).

• 109 Gm (0.7 au) Distance between Venus and the Sun
• 149.6 Gm (93.0 million mi; 1.0 au) – Distance between the Earth and the Sun – the original definition of the astronomical unit
• 180 Gm (1.2 au) – Maximum diameter of Sagittarius A*, the supermassive black hole in the center of Milky Way galaxy
• 228 Gm (1.5 au) – Distance between Mars and the Sun
• ≈280 Gm (1.9 au) – Diameter of Deneb, a blue supergiant and the brightest star in the Cygnus[155]
• 570 Gm (3.8 au) – Length of the tail of Comet Hyakutake measured by Ulysses; the actual value could be much higher
• ≈590 Gm (3.9 au) – Diameter of the Pistol Star, a blue hypergiant star[156]
• 591 Gm (4.0 au) – Minimum distance between the Earth and Jupiter
• 780 Gm (5.2 au) – Distance between Jupiter and the Sun
• 947 Gm (6.4 au) – Diameter of Antares A
• 965 Gm (6.4 au) – Maximum distance between the Earth and Jupiter

8 things in the terametre group

Comparison of size of the Kuiper belt (large faint torus) with the star VY Canis Majoris (within Saturn's orbit), Betelgeuse (inside Jupiter's orbit) and R Doradus (small central red sphere) together with the orbits of Neptune and Uranus, to scale. The yellow ellipses represent the orbits of each planet and the dwarf planet Pluto.

The terametre (SI symbol: Tm) is a unit of length in the metric system equal to 1000000000000 metres (10¹² m). To help compare different distances, this section lists lengths starting at 10¹² m (1 Tm or 1 billion km or 6.7 astronomical units).

• ≈1 Tm – 7 au – Diameter of the red supergiant Betelgeuse based on multiple angular diameter estimates[157]
• 1.079 Tm – 7.2 au – One light-hour
• 1.12 Tm – 7.5 au – mean diameter of Rho Cassiopeiae, a rare yellow hypergiant star.[158]
• 1.35 Tm – 9 au – Diameter of the H-alpha emission region around the blue hypergiant P Cygni[159]
• 1.4 Tm – 9.5 au – Distance between Saturn and the Sun
• 1.5 Tm – 10 au – Estimated diameter of VV Cephei A, a red supergiant with a blue dwarf companion.[160]
• 1.83 Tm – 12.2 au – Diameter of HR 5171 A, the largest-known yellow hypergiant star although the latest research suggests it is a red hypergiant with a diameter about 2.1 Tm (14 au)[161][162]
• 2 Tm – 13.2 au – Estimated diameter of both Mu Cephei and VY Canis Majoris, two red hypergiants that are among the largest-known stars[163][164][165]
• 2.9 Tm – 19.4 au – Distance between Uranus and the Sun
• 4.4 Tm – 29.4 au – Perihelion distance of Pluto
• 4.5 Tm – 30.1 au – Distance between Neptune and the Sun
• 4.5 Tm – 30.1 au – Inner radius of the Kuiper belt
• 5.7 Tm – 38.1 au – Perihelion distance of Eris
• 6.0 Tm – 40.5 au – Distance from Earth at which the Pale Blue Dot photograph was taken.
• 7.3 Tm – 48.8 au – Aphelion distance of Pluto
• 7.5 Tm – 50.1 au – Outer radius of the Kuiper Belt

Sedna's orbit (left) is longer than 100 Tm, but other lengths are between 10 and 100 Tm: Comet Hale-Bopp's orbit (lower, faint orange); one light-day (yellow spherical shell with yellow Vernal point arrow as radius); the heliosphere's termination shock (blue shell); and other arrows show positions of Voyager 1 (red) and Pioneer 10 (green). Click on image for larger view and links to other scales.

To help compare different distances this section lists lengths starting at 10¹³ m (10 Tm or 10 billion km or 67 astronomical units).

• 10 Tm – 67 AU – Diameter of a hypothetical quasi-star
• 11.1 Tm – 74.2 AU – Distance that Voyager 1 began detecting returning particles from termination shock
• 11.4 Tm – 76.2 AU – Perihelion distance of 90377 Sedna
• 12.1 Tm – 70 to 90 AU – Distance to termination shock (Voyager 1 crossed at 94 AU)
• 12.9 Tm – 86.3 AU – Distance to 90377 Sedna in March 2014
• 13.2 Tm – 88.6 AU – Distance to Pioneer 11 in March 2014
• 14.1 Tm – 94.3 AU – Estimated radius of the Solar System
• 14.4 Tm – 96.4 AU – Distance to Eris in March 2014 (now near its aphelion)
• 15.1 Tm – 101 AU – Distance to heliosheath
• 16.5 Tm – 111 AU – Distance to Pioneer 10 as of March 2014
• 16.6 Tm – 111.2 AU – Distance to Voyager 2 as of May 2016
• 20.0 Tm – 135 AU – Distance to Voyager 1 as of May 2016
• 20.6 Tm – 138 AU – Distance to Voyager 1 as of late February 2017
• 21.1 Tm – 141 AU – Distance to Voyager 1 as of November 2017
• 25.9 Tm – 173 AU – One light-day
• 30.8568 Tm – 206.3 AU – 1 milliparsec
• 55.7 Tm – 371 AU – Aphelion distance of the comet Hale-Bopp

The largest yellow sphere indicates one light month distance from the Sun. Click the image for larger view, more details and links to other scales.

To help compare different distances this section lists lengths starting at 10¹⁴ m (100 Tm or 100 billion km or 670 astronomical units).

• 140 Tm – 937 AU – Aphelion distance of 90377 Sedna
• 172 Tm – 1150 AU – Schwarzschild diameter of H1821+643, one of the most massive black holes known
• 181 Tm – 1210 AU – One light-week
• 308.568 Tm – 2063 AU – 1 centiparsec
• 757 Tm – 5059 AU – radius of the Stingray Nebula[166]
• 777 Tm – 5180 AU – One light-month

Largest circle with yellow arrow indicates one light-year from Sun; Cat's Eye Nebula on left and Barnard 68 in middle are depicted in front of Comet 1910 A1's orbit. Click image for larger view, details and links to other scales.

The petametre (SI symbol: Pm) is a unit of length in the metric system equal to 10¹⁵ metres. To help compare different distances this section lists lengths starting at 10¹⁵ m (1 Pm or 1 trillion km or 6685 astronomical units (AU) or 0.11 light-years).

• 1.0 Pm = 0.105702341 light-years[167]
• 1.9 Pm ± 0.5 Pm = 12,000 AU = 0.2 light-year radius of Cat's Eye Nebula's inner core[168]
• 3.08568 Pm = 20,626 AU = 1 deciparsec
• 4.7 Pm = 30,000 AU = half-light-year diameter of Bok globule Barnard 68[169]
• 7.5 Pm – 50,000 AU – Possible outer boundary of Oort cloud (other estimates are 75,000 to 125,000 or even 189,000 AU (1.18, 2, and 3 light-years, respectively))
• 9.5 Pm – 63,241.1 AU – One light-year, the distance traveled by light in one year
• 9.9 Pm – 66,000 AU – Aphelion distance of the C/1999 F1 (Catalina)

Objects with size order of magnitude 1e16m: Ten light-years (94.6 Pm) radius circle with yellow Vernal Point arrow; Bubble Nebula (NGC 7635), left; Dumbbell Nebula (NGC 6853), right; one light-year shell lower right with the smaller Cat's Eye Nebula (NGC_6543) and Barnard 68 adjacent.

1e16m lengths: Ten light-years (94.6 Pm) yellow shell; Sirius below right; BL Ceti below left; Proxima and Alpha Centauri upper right; light-year shell with Comet 1910 A1's orbit inside top right

To help compare different distances this section lists lengths starting at 10¹⁶ m (10 Pm or 66,800 AU, 1.06 light-years).

• 15 Pm – 1.59 light-years – Possible outer radius of Oort cloud
• 20 Pm – 2.11 light-years – maximum extent of influence of the Sun's gravitational field
• 30.9 Pm – 3.26 light-years – 1 parsec
• 39.9 Pm – 4.22 light-years – Distance to Proxima Centauri (nearest star to Sun)
• 81.3 Pm – 8.59 light-years – Distance to Sirius

Lengths with order of magnitude 1e17m: yellow Vernal Point arrow traces hundred light-year radius circle with smaller ten light-year circle at right; globular cluster Messier 5 in background; 12 light-year radius Orion Nebula middle right; 50-light-year-wide view of the Carina Nebula bottom left; Pleiades cluster and Bubble nebula with similar diameters each around 10 light-years bottom right; grey arrows show distances from Sun to stars Aldebaran (65 light-years) and Vega (25 light-years).

To help compare different distances this section lists lengths between 10¹⁷ m (100 Pm or 11 light-years) and 10¹⁸ m (106 light-years).

• 110 Pm – 12 light-years – Distance to Tau Ceti
• 230 Pm – 24 light-years – Diameter of the Orion Nebula[170][171]
• 240 Pm – 25 light-years – Distance to Vega
• 260 Pm – 27 light-years – Distance to Chara, a star approximately as bright as the Sun. Its faintness gives an idea how the Sun would appear when viewed from this distance.
• 308.568 Tm – 32.6 light-years – 1 dekaparsec
• 350 Pm – 37 light-years – Distance to Arcturus
• 373.1 Pm – 39.44 light-years – Distance to TRAPPIST-1, a star recently discovered to have 7 planets around it
• 400 Pm – 42 light-years – Distance to Capella
• 620 Pm – 65 light-years – Distance to Aldebaran
• 750 Pm – 79.36 light-years – Distance to Regulus
• 900 Pm – 92.73 light-years – Distance to Algol

Lengths with order of magnitude 1e18m: thousand light-year radius circle with yellow arrow and 100 light-year circle at right with globular cluster Messier 5 within and Carina Nebula in front; globular cluster Omega Centauri to left of both; part of the 1,400-light-year-wide Tarantula Nebula fills the background.

The exametre (SI symbol: Em) is a unit of length in the metric system equal to 10¹⁸ metres. To help compare different distances this section lists lengths between 10¹⁸ m (1 Em or 105.7 light-years) and 10¹⁹ m (10 Em or 1,057 light-years).

• 1.2 Em – 129 light-years – Diameter of Messier 13 (a typical globular cluster)
• 1.6 Em – 172 ± 12.5 light-years – Diameter of Omega Centauri (one of the largest-known globular clusters, perhaps containing over a million stars)[172][173]
• 3.08568 Em – 326.1 light-years – 1 hectoparsec
• 3.1 Em – 310 light-years – Distance to Canopus according to Hipparcos[174]
• 5.7 Em – 600 light-years – Diameter of the Tarantula Nebula
• 6.1 Em – 640 light-years – Distance to Betelgeuse according to Hipparcos[175]
• 6.2 Em – 650 light-years – Distance to the Helix Nebula, located in the constellation Aquarius[176]
• 7.3 Em – 730 light-years – Distance to Rigel according to Hipparcos[174]

To help compare different orders of magnitude, this section lists distances starting at 10 Em (10¹⁹ m or 1,100 light-years).

• 10.6 Em – 1,120 light-years – Distance to WASP-96b
• 13 Em – 1,300 light-years – Distance to the Orion Nebula[177]
• 14 Em – 1,500 light-years – Approximate thickness of the plane of the Milky Way galaxy at the Sun's location
• 14.2 Em – 1,520 light-years – Diameter of the NGC 604
• 30.8568 Em – 3,261.6 light-years – 1 kiloparsec
• 31 Em – 3,200 light-years – Distance to Deneb according to Hipparcos
• 46 Em – 4,900 light-years – Distance to OGLE-TR-56, the first extrasolar planet discovered using the transit method
• 47 Em – 5,000 light-years – Distance to the Boomerang nebula, coldest place known (1 K)
• 53 Em – 5,600 light-years – Distance to the globular cluster M4 and the extrasolar planet PSR B1620-26 b within it
• 61 Em – 6,500 light-years – Distance to Perseus Spiral Arm (next spiral arm out in the Milky Way galaxy)
• 71 Em – 7,500 light-years – Distance to Eta Carinae

To help compare different orders of magnitude, this section lists distances starting at 100 Em (10²⁰ m or 11,000 light-years).

• 150 Em – 16,000 light-years – Diameter of the Small Magellanic Cloud, a dwarf galaxy orbiting the Milky Way
• 200 Em – 21,500 light-years – Distance to OGLE-2005-BLG-390Lb, the most distant and the most Earth-like planet known
• 240 Em – 25,000 light-years – Distance to the Canis Major Dwarf Galaxy
• 260 Em – 28,000 light-years – Distance to the center of the Galaxy
• 400 Em – 48,000 light years – Diameter of the Fireworks Galaxy
• 830 Em – 88,000 light-years – Distance to the Sagittarius Dwarf Elliptical Galaxy

The zettametre (SI symbol: Zm) is a unit of length in the metric system equal to 10²¹ metres.[54] To help compare different orders of magnitude, this section lists distances starting at 1 Zm (10²¹ m or 110,000 light-years).

• 1.7 Zm – 179,000 light-years – Distance to the Large Magellanic Cloud, largest satellite galaxy of the Milky Way
• <1.9 Zm – <200,000 light-years – Revised estimated diameter of the disc of the Milky Way Galaxy. The size was previously thought to be half of this.
• 2.0 Zm – 210,000 light-years – Distance to the Small Magellanic Cloud
• 2.8 Zm – 300,000 light-years – Distance to the Intergalactic Wanderer, one of the most distant globular clusters of Milky Way
• 8.5 Zm – 900,000 light-years – Distance to the Leo I Dwarf Galaxy, farthest-known Milky Way satellite galaxy

To help compare different orders of magnitude, this section lists distances starting at 10 Zm (10²² m or 1.1 million light-years).

• 24 Zm – 2.5 million light-years – Distance to the Andromeda Galaxy
• 30.8568 Zm – 3.2616 million light-years – 1 megaparsec
• 40 Zm – 4.2 million light-years – Distance to the IC 10, a distant member of the Local Group of galaxies
• 49.2 Zm – 5.2 million light-years – Width of the Local Group of galaxies
• 95 Zm – 10 million light-years – Distance to the Sculptor Galaxy in the Sculptor Group of galaxies
• 95 Zm – 10 million light-years – Distance to the Maffei 1, the nearest giant elliptical galaxy in the Maffei 1 Group

To help compare different orders of magnitude, this section lists distances starting at 100 Zm (10²³ m or 11 million light-years).

• 140 Zm – 15 million light-years – Distance to Centaurus A galaxy
• 250 Zm – 27 million light-years – Distance to the Pinwheel Galaxy
• 280 Zm – 30 million light-years – Distance to the Sombrero Galaxy
• 570 Zm – 60 million light-years – Approximate distance to the Virgo cluster, nearest galaxy cluster
• 620 Zm – 65 million light-years – Approximate distance to the Fornax cluster
• 800 Zm – 85 million light-years – Approximate distance to the Eridanus cluster

The yottametre (SI symbol: Ym) is a unit of length in the metric system equal to 10²⁴ metres.[54]

To help compare different orders of magnitude, this section lists distances starting at 1 Ym (10²⁴ m or 105.702 million light-years).

• 1.2 Ym – 127 million light-years – Distance to the closest observed gamma ray burst GRB 980425
• 1.3 Ym – 137 million light-years – Distance to the Centaurus Cluster of galaxies, the nearest large supercluster
• 1.9 Ym – 201 million light-years – Diameter of the Local Supercluster
• 2.3 Ym – 225 to 250 million light-years – Distance light travels in vacuum in one galactic year
• 2.8 Ym – 296 million light-years – Distance to the Coma Cluster
• 3.15 Ym - 330 million light years - Diameter of the Boötes Void
• 3.2 Ym – 338 million light-years – Distance to Stephan's Quintet
• 4.7 Ym – 496 million light-years – Length of the CfA2 Great Wall, one of the largest observed superstructures in the Universe
• 6.1 Ym – 645 million light-years – Distance to the Shapley Supercluster
• 9.5 Ym – 996 million light-years – Diameter of the Eridanus Supervoid

The universe within one billion light-years of Earth

To help compare different orders of magnitude, this section lists distances starting at 10 Ym (10²⁵ m or 1.1 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depends on the cosmological models used.

• 13 Ym – 1.37 billion light-years – Length of the South Pole Wall
• 13 Ym – 1.38 billion light-years – Length of the Sloan Great Wall
• 18 Ym – redshift 0.16 – 1.9 billion light-years – Distance to the quasar 3C 273 (light travel distance)
• 30.8568 Ym – 3.2616 billion light-years – 1 gigaparsec
• 31.2204106 Ym − 3.3 billion light-years − Length of The Giant Arc, a large cosmic structure discovered in 2021
• 33 Ym – 3.5 billion light-years – Maximum distance of the 2dF Galaxy Redshift Survey (light travel distance)
• 37.8 Ym – 4 billion light-years – Length of the Huge-LQG
• 75 Ym – redshift 0.95 – 8 billion light-years – Approximate distance to the supernova SN 2002dd in the Hubble Deep Field North (light travel distance)
• 85 Ym – redshift 1.6 – 9 billion light-years – Approximate distance to the gamma-ray burst GRB 990123 (light travel distance)
• 94.6 Ym – 10 billion light-years – Approximate distance to quasar OQ172
• 94.6 Ym – 10 billion light-years – Length of the Hercules–Corona Borealis Great Wall, one of the largest and most massive-known cosmic structures known

To help compare different orders of magnitude, this section lists distances starting at 100 Ym (10²⁶ m or 11 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.

• 124 Ym – redshift 7.54 – 13.1 billion light-years – Light travel distance (LTD) to the quasar ULAS J1342+0928, the most distant-known quasar as of 2017
• 130 Ym – redshift 1,000 – 13.8 billion light-years – Distance (LTD) to the source of the cosmic microwave background radiation; radius of the observable universe measured as a LTD
• 260 Ym – 27.4 billion light-years – Diameter of the observable universe (double LTD)
• 440 Ym – 46 billion light-years – Radius of the universe measured as a comoving distance
• 590 Ym – 62 billion light-years – Cosmological event horizon: the largest comoving distance from which light will ever reach us (the observer) at any time in the future
• 886.48 Ym – 93.7 billion light-years – The diameter of the observable universe (twice the particle horizon); however, there might be unobserved distances that are even greater.

The ronnametre (SI symbol: Rm) is a unit of length in the metric system equal to 10²⁷ metres.[54]

To help compare different orders of magnitude, this section lists distances starting at 1 Rm (10²⁷ m or 110 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.

• >1 Rm - >105.7 billion light-years – Size of universe beyond the cosmic light horizon, depending on its curvature; if the curvature is zero (i.e. the universe is spatially flat), the value can be infinite (see Shape of the universe) as previously mentioned
• ≈10^1010120 Light-years – the possible size of the universe after cosmological inflation

• List of examples of lengths
• Fermi problem
• Scale (analytical tool)
• Spatial scale

• How Big Are Things? – displays orders of magnitude in successively larger rooms.
• Powers of Ten – Travel across the Universe.
• Cosmos – Journey from microcosmos to macrocosmos (Digital Nature Agency).
• Scale of the universe – interactive guide to length magnitudes
• Video (4:29) on YouTube – Orders of Magnitude (March 2020).