About the mg to kg calculation
One milligram is exactly 0.000001 kilograms, so converting between them is a single multiplication. Enter any value above and the result updates as you type. The usual unit for medication doses and nutrient quantities. The SI base unit of mass, and how bodyweight is quoted in most of the world.
Formula
kg = mg × 0.000001
1 mg = 0.000001 kg
1 kg = 1,000,000 mgWorked example
To convert 500 mg, multiply by 0.000001: 500 × 0.000001 = 0.0005 kg.
Frequently asked questions
How many kilograms are in a milligram?
There are 0.000001 kilograms in one milligram. To convert any amount, multiply the number of milligrams by 0.000001.
How do I convert kilograms back to milligrams?
Divide instead of multiplying, or equivalently multiply by 1,000,000. One kilogram is 1,000,000 milligrams.
Is this conversion exact?
Yes. Since the international agreement of 1959, the relationship between milligrams and kilograms is defined exactly rather than measured, so the only rounding here is in how many decimal places we show.
Where is each of these units used?
Milligrams: the usual unit for medication doses and nutrient quantities. Kilograms: the SI base unit of mass, and how bodyweight is quoted in most of the world.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units