Convert Micrograms to Milligrams
1 microgram (µg) equals 0.001 milligrams (mg).
1 µg = 0.001 mg
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk microgram to milligram converter to paste a column from Excel.
How to Convert Microgram to Milligram
- 1 µg = 0.001 mg
- 1 mg = 1000 µg
- Example: convert 15 µg to mg: 15 µg = 15 × 0.001 mg = 0.015 mg
Formula
mg = µg ÷ 1000
Derivation from SI units:
- 1 µg = 10⁻⁹ kg = 10⁻³ mg
- 1 mg = 10⁻⁶ kg = 10⁻³ g
- 1 µg = 1 × 10⁻⁹ kg ÷ 0.000001 kg per mg = 0.001 mg
Both units are defined exactly, so the factor is exact. Microgram definition: microgram; Milligram definition: milligram.
Worked examples
- A folic acid dose of 400 µg is 0.4 mg.
400 µg × 0.001 = 0.4 mg - A vitamin D dose of 25 µg is 0.025 mg.
25 µg × 0.001 = 0.025 mg
Microgram to Milligram conversion table
| Micrograms (µg) | Milligrams (mg) |
|---|---|
| 0.1 µg | 0.0001 mg |
| 1 µg | 0.001 mg |
| 5 µg | 0.005 mg |
| 10 µg | 0.01 mg |
| 25 µg | 0.025 mg |
| 50 µg | 0.05 mg |
| 100 µg | 0.1 mg |
| 125 µg | 0.125 mg |
| 150 µg | 0.15 mg |
| 200 µg | 0.2 mg |
| 250 µg | 0.25 mg |
| 400 µg | 0.4 mg |
| 500 µg | 0.5 mg |
| 1000 µg | 1 mg |
| 5000 µg | 5 mg |
Where it's used
Vitamin and hormone doses in micrograms (often written mcg) are converted to milligrams. Divide by 1000; mixing up mcg and mg is a 1000-fold dosing error.
Microgram to other weight and mass units
| Conversion | 1 µg equals |
|---|---|
| microgram to kilogram | 1 × 10⁻⁹ kg |
| microgram to gram | 0.000001 g |
| microgram to milligram | 0.001 mg |
| microgram to metric ton | 1 × 10⁻¹² t |
| microgram to pound | 2.204622622 × 10⁻⁹ lb |
| microgram to ounce | 3.527396195 × 10⁻⁸ oz |
| microgram to stone | 1.574730444 × 10⁻¹⁰ st |
| microgram to short ton | 1.102311311 × 10⁻¹² ton (US) |
| microgram to long ton | 9.842065276 × 10⁻¹³ ton (UK) |
| microgram to grain | 0.00001543235835 gr |
| microgram to troy ounce | 3.215074657 × 10⁻⁸ oz t |
| microgram to carat | 0.000005 ct |
Frequently asked questions
Is mcg the same as µg?
Yes. Labels write mcg to avoid misreading the µ symbol; 1 mcg = 1 µg = 0.001 mg.
How many milligrams are in 1 microgram?
1 µg = 0.001 mg.
How do I convert micrograms to milligrams?
Multiply the value in µg by 0.001, or divide it by 1000. For example, 15 µg × 0.001 = 0.015 mg.
Is the µg to mg conversion exact?
Yes. Both units are defined exactly, and 1 µg is exactly 0.001 mg.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Micrograms to Milligrams. Retrieved October 17, 2026, from https://scientificconverters.com/mass/micrograms-to-milligrams/
IEEE
Scientific Converters, "Convert Micrograms to Milligrams," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/mass/micrograms-to-milligrams/