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mcg to mg Converter

1 mg equals 1000 mcg, so 500 mcg is 0.5 mg. This converter switches between micrograms (mcg), milligrams (mg), and grams (g). Enter an amount and pick the units to read supplement and dosage labels with confidence, or to convert a prescription strength.

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Quick answer

There are 1000 micrograms in 1 milligram.

Result

0.5 mg

What this tells you

  • There are 1000 micrograms in 1 milligram.
  • There are 1000 milligrams in 1 gram.
  • mcg is the same as the symbol ug, used for micrograms.
  • Switch the from and to units to convert in either direction.

How to Use

  1. 1Enter the amount you want to convert.
  2. 2Choose the unit you are converting from.
  3. 3Choose the unit you are converting to.
  4. 4Read the converted amount below.

How It Works

Formula

mg = mcg / 1000

Micrograms, milligrams, and grams each step up by a factor of 1000. To convert micrograms to milligrams, divide by 1000. To convert milligrams to micrograms, multiply by 1000. Grams are 1000 times larger than milligrams.

Calculation note: values are processed in the order shown above, using the current input units.

Worked Examples

Convert 500 mcg to mg

Value500
Frommcg
Tomg
Result0.5 mg

Divide 500 by 1000 to get 0.5 mg.

Convert 2 mg to mcg

Value2
Frommg
Tomcg
Result2000 mcg

Multiply 2 by 1000 to get 2000 mcg.

Microgram, Milligram, and Gram Conversions

How the three units relate.

AmountIn mcgIn mgIn g
1 mcg10.0010.000001
1 mg1,00010.001
1 g1,000,0001,0001
25 mcg250.0250.000025
500 mcg5000.50.0005

mcg and ug both mean micrograms. The symbol ug is sometimes used where the Greek letter is unavailable.

Common mistakes

  • Confusing mcg and mg. They differ by 1000 times, so 1000 mcg is only 1 mg.
  • Reading ug as a different unit. ug and mcg both mean micrograms.
  • Assuming mcg converts to IU. International units are substance specific and do not convert by a fixed factor.

Frequently Asked Questions

There are 1000 micrograms (mcg) in 1 milligram (mg).
Divide the microgram amount by 1000. For example, 500 mcg divided by 1000 is 0.5 mg.
Multiply the milligram amount by 1000. For example, 2 mg times 1000 is 2000 mcg.
Yes. mcg and ug both mean micrograms. The symbol ug is used when the Greek letter mu is not available, but the value is identical.
Yes. 1000 micrograms equals exactly 1 milligram.
It estimates mcg to mg converter outputs using the visible inputs and formula assumptions on this page.

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