How to Convert Grams to Milligrams

Co-authored by Sophia Latorre

Last Updated: October 5, 2022 References

Converting grams (g) to milligrams (mg) is an easy task! All you need to do is multiply by the number of grams by 1,000. If you want to convert milligrams to grams, simply divide the number of milligrams by 1,000.

Method 1

Method 1 of 2:

Changing Grams into Milligrams

1
Recognize that “milli” means one-thousandth. Understanding the definition of the prefix can help you remember the difference between grams and milligrams. Since “milli” means one-thousandth, a milligram is 1/1,000 of a gram.^{[1]
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2
Multiply the number of grams (g) by 1,000 to get milligrams (mg). Multiplying by 1,000 is the same as moving the decimal point 3 spots to the right.^{[2]
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- For example, say you have 75 grams. Simply multiply 75 by 1,000, which equals 75,000. So, 75 grams (g) is equal to 75,000 milligrams (mg).^{[3]
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3
Understand that grams (g) and milligrams (mg) measure mass. Both grams and milligrams are units used to measure mass, or how heavy an object is.^{[4]
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Method 2

Method 2 of 2:

Converting Milligrams to Grams

1
Note that milligrams (mg) are smaller than grams (g). Since “milli” means “one-thousandth,” a milligram is one-thousandth the size of a gram. Therefore, there will be fewer grams than milligrams.^{[5]
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2
Divide the number of milligrams (mg) by 1,000 to find the number of grams (g). Keep in mind that there are 1,000 milligrams in every gram.^{[6]
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- For instance, if you have 500,000 milligrams, divide 500,000 by 1,000, which equals 500. Therefore, 500,000 milligrams (mg) is equal to 500 grams (g).^{[7]
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3
Remember that milligrams (mg) and grams (g) are metric units. If you live in the United States or another country that uses the imperial measurement system, you may be unfamiliar with grams and milligrams, since they are metric units. In the U.S., ounces (oz) and pounds (lbs) are usually used to measure weight.^{[8]
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