Milligrams to Micrograms Converter (mg to mcg)
1 mg = 1,000 mcg (µg). Convert milligrams to micrograms to compare supplement doses and medicine strengths, with mg to mcg and mcg to mg charts.
Microgram (µg) = Milligram (mg) × 1000
Milligram (mg): A milligram is one thousandth of a gram, or one millionth of a kilogram. There are 1,000 micrograms in one milligram.
Microgram (µg): A microgram is one millionth of a gram, or one billionth of a kilogram. The SI symbol is µg; this converter also accepts mcg and ug as aliases.
| Milligram (mg) | Microgram (µg) |
|---|---|
| 1 | 1000 |
| 5 | 5000 |
| 10 | 10000 |
| 25 | 25000 |
| 50 | 50000 |
| 100 | 100000 |
Small doses written as decimals of a milligram, such as 0.125 mg or 0.05 mg, are easy to misread. Converting them to micrograms turns them into whole numbers, 125 mcg and 50 mcg, which is how many thyroid, heart and vitamin products are labeled today. Whole micrograms also avoid the missing leading zero, where .125 mg could be read as 125 mg.
The same step helps when one supplement lists copper or manganese in milligrams and another lists it in micrograms. Multiplying milligrams by 1,000 gives micrograms exactly; the charts run from 0.001 mg, a single microgram, up to 10 mg, which is 10,000 mcg.
How to use this tool
- Type a value in the Milligram box to see it in micrograms, or type in the Microgram box to convert the other way.
- Press ⇄ to swap the two units, or Load example for a typical value.
- Check the charts below for common values; for other units, open the Weight & Mass converter.
Formula
Microgram (µg) = Milligram (mg) × 1000
Milligram (mg) = Microgram (µg) × 0.001
Both factors come from exact definitions: 1 microgram = 0.001 milligrams and 1 milligram = 1000 micrograms (shown to 12 significant digits).
Example
Two conversions worked with the same factors the converter uses:
0.125 mg × 1000 = 125 µg
2500 µg × 0.001 = 2.5 mg
Milligram to Microgram chart
Common values from milligrams to micrograms, rounded to four decimal places.
| Milligram (mg) | Microgram (µg) |
|---|---|
| 0.001 | 1 |
| 0.005 | 5 |
| 0.01 | 10 |
| 0.02 | 20 |
| 0.05 | 50 |
| 0.088 | 88 |
| 0.1 | 100 |
| 0.125 | 125 |
| 0.137 | 137 |
| 0.2 | 200 |
| 0.25 | 250 |
| 0.4 | 400 |
| 0.5 | 500 |
| 0.75 | 750 |
| 0.9 | 900 |
| 1 | 1,000 |
| 1.2 | 1,200 |
| 1.3 | 1,300 |
| 1.7 | 1,700 |
| 2 | 2,000 |
| 2.3 | 2,300 |
| 3 | 3,000 |
| 5 | 5,000 |
| 10 | 10,000 |
Microgram to Milligram chart
The reverse direction for values people often look up.
| Microgram (µg) | Milligram (mg) |
|---|---|
| 3 | 0.003 |
| 12 | 0.012 |
| 35 | 0.035 |
| 45 | 0.045 |
| 60 | 0.06 |
| 90 | 0.09 |
| 112 | 0.112 |
| 137 | 0.137 |
| 300 | 0.3 |
| 700 | 0.7 |
| 900 | 0.9 |
| 1,500 | 1.5 |
| 3,000 | 3 |
Milligram amounts often restated in micrograms
| Item | Milligram (mg) | Microgram (µg) |
|---|---|---|
| Digoxin tablet, a common low strength | 0.125 | 125 |
| Digoxin tablet, a common higher strength | 0.25 | 250 |
| Daily Value for copper | 0.9 | 900 |
| Daily Value for thiamin (vitamin B1) | 1.2 | 1,200 |
| Daily Value for riboflavin (vitamin B2) | 1.3 | 1,300 |
| Daily Value for vitamin B6 | 1.7 | 1,700 |
| Daily Value for manganese | 2.3 | 2,300 |
Quick mental estimate
Multiply by 1,000, which turns decimal doses into whole numbers: 0.125 mg → 125 mcg and 0.9 mg → 900 mcg. The step is exact, so the only thing to check is that the result grew a thousandfold.
Use the converter or the charts when the exact figure matters.
The two units
Milligram (mg): A milligram is one thousandth of a gram, or one millionth of a kilogram. There are 1,000 micrograms in one milligram.
Microgram (µg): A microgram is one millionth of a gram, or one billionth of a kilogram. The SI symbol is µg; this converter also accepts mcg and ug as aliases.
Frequently asked questions
How many micrograms are in a milligram?
Exactly 1,000. A microgram is one millionth of a gram and a milligram one thousandth, so each milligram holds a thousand micrograms. Going the other way, divide micrograms by 1,000 to get milligrams.
Why do some labels say 0.1 mg and others 100 mcg?
They are the same amount: 0.1 mg is 100 mcg. Older labels and some prescriptions write small doses as decimal milligrams, while many newer labels use whole micrograms, so check the unit before comparing two products.
Is a 1 mg dose twice as much as 500 mcg?
Yes. 1 mg is 1,000 mcg, which is double 500 mcg. Mixing the units up the other way, reading 500 mcg as 500 mg, would be a thousandfold error. Two 500 mcg tablets together make up a 1 mg dose.
How precise is the result?
The converter uses the exact definitions above with browser floating-point arithmetic and shows up to 12 significant digits. The charts round to four decimal places for reading.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/milligram-to-microgram-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). Milligrams to Micrograms Converter (mg to mcg). https://kakao.mobile/tools/milligram-to-microgram-converter/
“Milligrams to Micrograms Converter (mg to mcg).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/milligram-to-microgram-converter/.
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