This converter turns micrograms into milligrams instantly, using the exact factor 1 microgram = 0.001 milligrams. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
One millionth of a gram, used for vitamins, hormones and trace analysis. One thousandth of a gram, the standard unit for medication doses and nutrients.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
micrograms- The amount you are converting, measured in micrograms
0.001- The exact number of milligrams in one microgram
milligrams- The converted result
How it works, step by step
- Enter the number of micrograms you want to convert.
- The value is multiplied by 0.001, the exact conversion factor.
- The result is displayed in milligrams, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 micrograms
Multiply 5 by 0.001. That gives 0.005 milligrams. A quick sanity check: one microgram is smaller than one milligram, so the number should get smaller — and it does.
Converting 72 micrograms
72 × 0.001 = 0.072 milligrams. Working backwards, 0.072 ÷ 0.001 returns 72 micrograms, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many milligrams are in one microgram?
Exactly 0.001. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert micrograms to milligrams?
Milligrams = micrograms × 0.001. To reverse it, divide instead: micrograms = milligrams ÷ 0.001, which is the same as multiplying by 1000.
Is the microgram bigger than the milligram?
No. One microgram is only 0.001 of a milligram, so the milligram is the larger unit.
Why does my answer differ slightly from other micrograms to mg converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a microgram?
One millionth of a gram, used for vitamins, hormones and trace analysis.
What is a milligram?
One thousandth of a gram, the standard unit for medication doses and nutrients.
Micrograms to milligrams reference table
| Micrograms | Milligrams |
|---|---|
| 0.5 µg | 0.0005 mg |
| 1 µg | 0.001 mg |
| 2 µg | 0.002 mg |
| 3 µg | 0.003 mg |
| 5 µg | 0.005 mg |
| 10 µg | 0.01 mg |
| 15 µg | 0.015 mg |
| 20 µg | 0.02 mg |
| 25 µg | 0.025 mg |
| 50 µg | 0.05 mg |
| 75 µg | 0.075 mg |
| 100 µg | 0.1 mg |
| 250 µg | 0.25 mg |
| 500 µg | 0.5 mg |
| 1000 µg | 1 mg |
Exact factor: 1 microgram = 0.001 milligrams. Values rounded for display.