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Convert Milligrams to Micrograms

1 milligram is 1,000 mcg. One milligram is exactly 1000 micrograms.

One milligram is 1000 micrograms. To convert milligrams to micrograms, multiply by 1000; to go the other way, divide by 1000 or multiply by 0.001. The factor is exact rather than rounded: it follows from NIST Handbook 44. One thousandth of a gram, and exactly 1,000 micrograms.

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Micrograms
1,000 mcg
Milligrams × 1000
value * 10001,000 mcg

1 milligram in every weight unit

UnitValueExact factor
ounces0.00003527396195 oz× 0.0000352739619496
pounds0.000002204622622 lb× 0.00000220462262185
stone0.0000001574730444 st× 0.000000157473044418
US tons0.000000001102311311 ton× 0.00000000110231131092
micrograms1,000 mcg× 1,000
milligrams (as entered)1 mg
grams0.001 g× 0.001
kilograms0.000001 kg× 0.000001
tonnes0.000000001 t× 0.000000001

Factors are entered by hand from NIST Handbook 44 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert milligrams to micrograms?

  1. 1.Take the measurement in milligrams.
  2. 2.Multiply by 1000 — that is how many micrograms fit in one milligram.
  3. 3.To go back the other way, divide by 1000, or multiply by 0.001.

Milligrams to micrograms conversion table

MilligramsMicrograms
1 mg1,000 mcg
2 mg2,000 mcg
3 mg3,000 mcg
4 mg4,000 mcg
5 mg5,000 mcg
6 mg6,000 mcg
7 mg7,000 mcg
8 mg8,000 mcg
9 mg9,000 mcg
10 mg10,000 mcg
12 mg12,000 mcg
15 mg15,000 mcg
20 mg20,000 mcg
25 mg25,000 mcg
50 mg50,000 mcg
100 mg100,000 mcg

What are milligrams and micrograms?

Milligram (mg)
One thousandth of a gram, and exactly 1,000 micrograms. The unit almost every medicine is dosed in.
Microgram (mcg)
One millionth of a gram. Written mcg rather than µg on labels deliberately: the Greek letter is the character most often lost in transcription, and a factor of a thousand in a dose is not a rounding error.

Source: NIST Handbook 44 — mass and weight

Questions people actually ask

How many micrograms are in a milligram?
1000. One millionth of a gram. Written mcg rather than µg on labels deliberately: the Greek letter is the character most often lost in transcription, and a factor of a thousand in a dose is not a rounding error.
How do I convert micrograms back to milligrams?
Divide by 1000, or multiply by 0.001 — they are the same operation.

Other weight conversions

Micrograms to milligrams — the same conversion the other way.

Calculators that work in weight