Micrograms to Milligrams Converter (mcg to mg)
1 mcg (µg) = 0.001 mg, so 1,000 mcg = 1 mg. Convert micrograms to milligrams for vitamin labels and prescriptions, with mcg and mg charts.
Milligram (mg) = Microgram (µg) × 0.001
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): A milligram is one thousandth of a gram, or one millionth of a kilogram. There are 1,000 micrograms in one milligram.
| Microgram (µg) | Milligram (mg) |
|---|---|
| 1 | 0.001 |
| 5 | 0.005 |
| 10 | 0.01 |
| 25 | 0.025 |
| 50 | 0.05 |
| 100 | 0.1 |
Vitamins and trace minerals are needed in tiny amounts, so US Supplement Facts and Nutrition Facts labels give vitamin D, vitamin B12, folate, iodine and selenium in micrograms. Other products, and some older references, give the same nutrients in milligrams, which makes side-by-side comparisons confusing until both are in the same unit.
The microgram is one thousandth of a milligram. Its SI symbol is µg, but labels and prescriptions in the US write mcg instead for the same unit, because a handwritten µ can be mistaken for an m, which would make the dose a thousand times larger.
How to use this tool
- Type a value in the Microgram box to see it in milligrams, or type in the Milligram 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
Milligram (mg) = Microgram (µg) × 0.001
Microgram (µg) = Milligram (mg) × 1000
Both factors come from exact definitions: 1 milligram = 1000 micrograms and 1 microgram = 0.001 milligrams (shown to 12 significant digits).
Example
Two conversions worked with the same factors the converter uses:
400 µg × 0.001 = 0.4 mg
0.05 mg × 1000 = 50 µg
Microgram to Milligram chart
Common values from micrograms to milligrams, rounded to four decimal places.
| Microgram (µg) | Milligram (mg) |
|---|---|
| 1 | 0.001 |
| 2.4 | 0.0024 |
| 5 | 0.005 |
| 10 | 0.01 |
| 15 | 0.015 |
| 20 | 0.02 |
| 25 | 0.025 |
| 30 | 0.03 |
| 50 | 0.05 |
| 55 | 0.055 |
| 75 | 0.075 |
| 88 | 0.088 |
| 100 | 0.1 |
| 120 | 0.12 |
| 125 | 0.125 |
| 150 | 0.15 |
| 175 | 0.175 |
| 200 | 0.2 |
| 250 | 0.25 |
| 400 | 0.4 |
| 500 | 0.5 |
| 600 | 0.6 |
| 800 | 0.8 |
| 1,000 | 1 |
| 2,500 | 2.5 |
| 5,000 | 5 |
| 10,000 | 10 |
Milligram to Microgram chart
The reverse direction for values people often look up.
| Milligram (mg) | Microgram (µg) |
|---|---|
| 0.001 | 1 |
| 0.01 | 10 |
| 0.025 | 25 |
| 0.05 | 50 |
| 0.075 | 75 |
| 0.1 | 100 |
| 0.112 | 112 |
| 0.125 | 125 |
| 0.15 | 150 |
| 0.2 | 200 |
| 0.3 | 300 |
| 0.5 | 500 |
| 1 | 1,000 |
Microgram amounts on US labels
| Item | Microgram (µg) | Milligram (mg) |
|---|---|---|
| Daily Value for vitamin B12 | 2.4 | 0.0024 |
| Daily Value for vitamin D | 20 | 0.02 |
| Daily Value for biotin | 30 | 0.03 |
| Daily Value for selenium | 55 | 0.055 |
| A common levothyroxine tablet strength | 100 | 0.1 |
| Daily Value for vitamin K | 120 | 0.12 |
| Daily Value for iodine | 150 | 0.15 |
| Daily folic acid the CDC advises for women | 400 | 0.4 |
Quick mental estimate
Divide by 1,000 by shifting the decimal point three places left: 400 mcg → 0.4 mg and 25 mcg → 0.025 mg. As a sense check, any amount under 1,000 mcg must come out under 1 mg. The conversion is exact.
Use the converter or the charts when the exact figure matters.
The two units
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): A milligram is one thousandth of a gram, or one millionth of a kilogram. There are 1,000 micrograms in one milligram.
Frequently asked questions
Is mcg the same as µg?
Yes. Both mean microgram, one millionth of a gram. Medication-safety guidance in the US prefers mcg because a handwritten µg can be misread as mg.
Why does my vitamin D label show mcg and IU?
Since the 2016 update to US nutrition labels, vitamin D is declared in micrograms, and makers may add international units in parentheses. For vitamin D, 1 mcg equals 40 IU, so the 20 mcg Daily Value matches 800 IU.
Is 1,000 mcg of vitamin B12 the same as 1 mg?
Yes, 1,000 mcg is exactly 1 mg. Supplement doses of B12 are often far above the 2.4 mcg Daily Value, so check which unit a label uses before comparing products. A 1,000 mcg tablet holds more than 400 times the Daily Value.
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/microgram-to-milligram-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). Micrograms to Milligrams Converter (mcg to mg). https://kakao.mobile/tools/microgram-to-milligram-converter/
“Micrograms to Milligrams Converter (mcg to mg).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/microgram-to-milligram-converter/.
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