Convert Milligrams to Grams
1 milligram (mg) equals 0.001 grams (g).
1 mg = 0.001 g
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk milligram to gram converter to paste a column from Excel.
How to Convert Milligram to Gram
- 1 mg = 0.001 g
- 1 g = 1000 mg
- Example: convert 15 mg to g: 15 mg = 15 × 0.001 g = 0.015 g
Formula
g = mg ÷ 1000
Derivation from SI units:
- 1 mg = 10⁻⁶ kg = 10⁻³ g
- 1 g = 10⁻³ kg
- 1 mg = 0.000001 kg ÷ 0.001 kg per g = 0.001 g
Both units are defined exactly, so the factor is exact. Milligram definition: milligram; Gram definition: gram.
Worked examples
- A 500 mg tablet contains 0.5 g of active ingredient.
500 mg × 0.001 = 0.5 g - A daily sodium limit of 2300 mg is 2.3 g.
2300 mg × 0.001 = 2.3 g
Milligram to Gram conversion table
| Milligrams (mg) | Grams (g) |
|---|---|
| 0.1 mg | 0.0001 g |
| 0.5 mg | 0.0005 g |
| 1 mg | 0.001 g |
| 2 mg | 0.002 g |
| 5 mg | 0.005 g |
| 10 mg | 0.01 g |
| 20 mg | 0.02 g |
| 25 mg | 0.025 g |
| 50 mg | 0.05 g |
| 65 mg | 0.065 g |
| 81 mg | 0.081 g |
| 100 mg | 0.1 g |
| 200 mg | 0.2 g |
| 250 mg | 0.25 g |
| 325 mg | 0.325 g |
| 400 mg | 0.4 g |
| 500 mg | 0.5 g |
| 1000 mg | 1 g |
| 2000 mg | 2 g |
| 5000 mg | 5 g |
Where it's used
Doses and nutrient amounts in milligrams are converted to grams for formulation, batch calculations and nutrition totals. Divide by 1000.
Milligram to other weight and mass units
| Conversion | 1 mg equals |
|---|---|
| milligram to kilogram | 0.000001 kg |
| milligram to gram | 0.001 g |
| milligram to microgram | 1000 µg |
| milligram to metric ton | 1 × 10⁻⁹ t |
| milligram to pound | 0.000002204622622 lb |
| milligram to ounce | 0.00003527396195 oz |
| milligram to stone | 1.574730444 × 10⁻⁷ st |
| milligram to short ton | 1.102311311 × 10⁻⁹ ton (US) |
| milligram to long ton | 9.842065276 × 10⁻¹⁰ ton (UK) |
| milligram to grain | 0.01543235835 gr |
| milligram to troy ounce | 0.00003215074657 oz t |
| milligram to carat | 0.005 ct |
Frequently asked questions
How many mg are in a gram?
Exactly 1000.
How many grams are in 1 milligram?
1 mg = 0.001 g.
How do I convert milligrams to grams?
Multiply the value in mg by 0.001, or divide it by 1000. For example, 15 mg × 0.001 = 0.015 g.
Is the mg to g conversion exact?
Yes. Both units are defined exactly, and 1 mg is exactly 0.001 g.
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 Milligrams to Grams. Retrieved October 17, 2026, from https://scientificconverters.com/mass/milligrams-to-grams/
IEEE
Scientific Converters, "Convert Milligrams to Grams," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/mass/milligrams-to-grams/