This converter turns milligrams into kilograms instantly, using the exact factor 1 milligram = 1e-06 kilograms. 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 thousandth of a gram, the standard unit for medication doses and nutrients. The SI base unit of mass, redefined in 2019 in terms of the Planck constant.
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
milligrams- The amount you are converting, measured in milligrams
1e-06- The exact number of kilograms in one milligram
kilograms- The converted result
How it works, step by step
- Enter the number of milligrams you want to convert.
- The value is multiplied by 1e-06, the exact conversion factor.
- The result is displayed in kilograms, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 milligrams
Multiply 5 by 1e-06. That gives 0.000005 kilograms. A quick sanity check: one milligram is smaller than one kilogram, so the number should get smaller — and it does.
Converting 72 milligrams
72 × 1e-06 = 0.000072 kilograms. Working backwards, 0.000072 ÷ 1e-06 returns 72 milligrams, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many kilograms are in one milligram?
Exactly 1e-06. 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 milligrams to kilograms?
Kilograms = milligrams × 1e-06. To reverse it, divide instead: milligrams = kilograms ÷ 1e-06, which is the same as multiplying by 1000000.
Is the milligram bigger than the kilogram?
No. One milligram is only 1e-06 of a kilogram, so the kilogram is the larger unit.
Why does my answer differ slightly from other mg to kg 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 milligram?
One thousandth of a gram, the standard unit for medication doses and nutrients.
What is a kilogram?
The SI base unit of mass, redefined in 2019 in terms of the Planck constant.
Milligrams to kilograms reference table
| Milligrams | Kilograms |
|---|---|
| 0.5 mg | 5.0000e-07 kg |
| 1 mg | 0.000001 kg |
| 2 mg | 0.000002 kg |
| 3 mg | 0.000003 kg |
| 5 mg | 0.000005 kg |
| 10 mg | 0.00001 kg |
| 15 mg | 0.000015 kg |
| 20 mg | 0.00002 kg |
| 25 mg | 0.000025 kg |
| 50 mg | 0.00005 kg |
| 75 mg | 0.000075 kg |
| 100 mg | 0.0001 kg |
| 250 mg | 0.00025 kg |
| 500 mg | 0.0005 kg |
| 1000 mg | 0.001 kg |
Exact factor: 1 milligram = 1e-06 kilograms. Values rounded for display.