How to Convert Inches to Centimeters

There are many tools for converting inches to centimeters on the web, all of which will tell you that 1 inch = 2.54 cm. However, in academic situations, this information is sometimes insufficient, as many teachers will require you to show your work. Luckily, converting inches to centimeters using algebraic steps and proper unit cancellation is a fairly simple task. If your initial measurements are in inches, the process is as simple as plugging your values into the blank space in the simple formula provided in this article and following the calculations. See Step 1 below to get started.

Inches to Centimeters Converter

Method 1

Method 1 of 2:

Converting via Simplified Process

1
Write your length value in inches. Either use the value you have been given (as part of a homework problem, etc.) or use a ruler or tape measure to measure the length you wish to convert.^{[1]
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2
Multiply your length value by 2.54. One inch is equal to roughly 2.54 centimeters, so converting inches to centimeters means multiplying a value in inches by 2.54.^{[2]
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3
Label your new value as centimeters. Don't forget to include the correct label on your new value. If you're doing schoolwork, using the wrong label can result in points deducted form your answer or even your answer being marked as wrong.^{[3]
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Method 2

Method 2 of 2:

Converting via Detailed Process

1
Ensure your measurement is in inches. This may seem like a no-brainer, but it's important to remember, especially when dealing with mixed measurements of feet and inches, which are often denoted by apostrophe markings, like this: 6'2". Remember that in such measurements the number marked by the single apostrophe is feet, each of which contains 12 inches.^{[4]
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- For example, in the example above, 6'2", we would multiply 6 feet by 12 inches/foot to get 72 inches total. To this we'll add the extra two inches from our measurement to get a final value of 74 inches.
2
Insert your value (in inches) into the inches to centimeters conversion factor below.
____ in * 2.54 cm
1 in = ? cm
This conversion factor will get you an accurate answer in centimeters and satisfy most "show your work" requirements, if you're a student. Simply place your value for inches into the blank at the beginning of the conversion factor and multiply through.
- This conversion factor will also get you the correct units. Note that the "inches" label in the denominator of the conversion factor cancels with the "inches" label of the value you plug in, leaving only the "centimeters" label in the numerator of the conversion factor for your final answer.
- Let's try plugging our example of 74 inches into the conversion factor.
  - (74 inches × 2.54 centimeters)/(1 inch)
  - (187.96 inches × centimeters)/(1 inch)
  - We cancel the "inch" labels because they appear once in both the numerator and the denominator, leaving us with a final answer of 187.96 centimeters.
3
Simply use a calculator if you don't need to show your work. If you're not interested in showing your work for academic purposes, all you need to do to convert inches to centimeters is multiply your inches value by 2.54 on a calculator. This is essentially the same as performing the calculations in the formula above, and will get you the same result in centimeters.^{[5]
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- For example, if we want to know the value of 6 inches in centimeters, we would just multiply 6 × 2.54 = 15.24 cm.
4
For on-the-fly mental calculations, round your conversion factor to an easier value. If you don't have a calculator handy, it's still possible to approximate an inches-to-centimeters conversion by using a "rounder" conversion factor to make mental multiplication easier. Instead of using the precise conversion factor of 2.54 centimeters/1 inch, use 2.5 centimeters/1 inch. Note that this will cause your final answer to be slightly inaccurate, so this method is only suitable for situations in which loose estimations are acceptable.
- For instance, let's convert 31 inches to centimeters using this quick estimation method:
  - 2.5 × 30 = 75. 2.5 × 1 = 2.5
  - 75 + 2.5 = 77.5 centimeters.
  - Note that if we had used the precise conversion factor of 2.54 centimeters/1 inch, our answer would have been 78.74 centimeters. These two answers differ by 1.24 centimeters, or about 1.5%.

Community Q&A

Question

To find the number of centimeters in 10 inches, by what do I multiply the number of inches given (10)?

Community Answer

There are 2.5 centimeters in 1 inch. So you would multiply the number of inches given, in this case 10, to get the number of centimeters, 25.
Question

How long is 22 cm in inches?

Community Answer

Just divide 22 by 2.54. 22/2.54 = 8.66.
Question

What is 1 3/4 inches in millimeters?

Donagan

Top Answerer

Multiply inches by 25.4.