Convert Milligrams to Kilograms
1 milligram (mg) equals 0.000001 kilograms (kg).
1 mg = 0.000001 kg
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk milligram to kilogram converter to paste a column from Excel.
How to Convert Milligram to Kilogram
- 1 mg = 0.000001 kg
- 1 kg = 1000000 mg
- Example: convert 15 mg to kg: 15 mg = 15 × 0.000001 kg = 0.000015 kg
Formula
kg = mg ÷ 1000000
Derivation from SI units:
- 1 mg = 10⁻⁶ kg = 10⁻³ g
- SI base unit, fixed by the Planck constant h = 6.626 070 15 × 10⁻³⁴ J·s
Both units are defined exactly, so the factor is exact. Milligram definition: milligram; Kilogram definition: kilogram.
Worked examples
- A reading of 20 mg converts to 0.00002 kg.
20 mg × 0.000001 = 0.00002 kg - A value of 250 mg is 0.00025 kg.
250 mg × 0.000001 = 0.00025 kg
Milligram to Kilogram conversion table
| Milligrams (mg) | Kilograms (kg) |
|---|---|
| 0.1 mg | 1 × 10⁻⁷ kg |
| 0.5 mg | 5 × 10⁻⁷ kg |
| 1 mg | 0.000001 kg |
| 2 mg | 0.000002 kg |
| 5 mg | 0.000005 kg |
| 10 mg | 0.00001 kg |
| 20 mg | 0.00002 kg |
| 25 mg | 0.000025 kg |
| 50 mg | 0.00005 kg |
| 65 mg | 0.000065 kg |
| 81 mg | 0.000081 kg |
| 100 mg | 0.0001 kg |
| 200 mg | 0.0002 kg |
| 250 mg | 0.00025 kg |
| 325 mg | 0.000325 kg |
| 400 mg | 0.0004 kg |
| 500 mg | 0.0005 kg |
| 1000 mg | 0.001 kg |
| 2000 mg | 0.002 kg |
| 5000 mg | 0.005 kg |
Where it's used
Milligrams are used for medication doses (e.g. 500 mg tablets), while kilograms appear in body weight and food packaging. Both measure mass (commonly called weight), so the conversion is a fixed factor.
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 kilograms are in 1 milligram?
1 mg = 0.000001 kg.
How do I convert milligrams to kilograms?
Multiply the value in mg by 0.000001, or divide it by 1000000. For example, 15 mg × 0.000001 = 0.000015 kg.
Is the mg to kg conversion exact?
Yes. Both units are defined exactly, and 1 mg is exactly 0.000001 kg.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Section 2.3.1, base unit definitions.
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 Kilograms. Retrieved October 17, 2026, from https://scientificconverters.com/mass/milligrams-to-kilograms/
IEEE
Scientific Converters, "Convert Milligrams to Kilograms," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/mass/milligrams-to-kilograms/