Milligrams to Kilograms
Type a value in either box to convert between milligrams and kilograms. The factor is 1e-06.
| Milligrams | Kilograms |
|---|---|
| 1 mg | 1e-06 kg |
| 2 mg | 2e-06 kg |
| 3 mg | 3e-06 kg |
| 5 mg | 5e-06 kg |
| 10 mg | 1e-05 kg |
| 25 mg | 2.5e-05 kg |
| 50 mg | 5e-05 kg |
| 100 mg | 0.0001 kg |
How to use
- Enter a value in the Milligrams field.
- The Kilograms figure appears immediately — no button to press.
- Typing in the Kilograms field converts back to Milligrams the same way.
- Use the reference table for the values that come up most often.
Milligrams to Kilograms formula
The factor from milligrams to kilograms is 1e-06.
kg = mg × 1e-06
Why this factor: the milligram and the kilogram are both defined against the kilogram, so dividing one definition by the other gives 1e-06 directly. Both definitions are set out in full below.
To go the other way, divide by 1e-06 — or use the Kilograms to Milligrams converter, which is the same calculation reversed.
Worked example
Take 2 mg and multiply by the factor 1e-06: the result is 2e-06 kg.
2 mg × 1e-06 = 2e-06 kg
The converter above does this for any value you type, in either direction.
What is a milligram?
A milligram is one thousandth of a gram — the standard unit for drug doses and micronutrients.
Definition: Exactly 1×10⁻⁶ kilogram by SI prefix definition.
Where it is used: Medication dosages, vitamin and mineral content, and analytical chemistry.
What is a kilogram?
The kilogram is the SI base unit of mass — the reference for every other mass unit.
Definition: Since 2019 the kilogram has been defined by fixing the Planck constant at exactly 6.62607015×10⁻³⁴ joule-seconds, retiring the physical platinum-iridium cylinder that defined it for 130 years.
Where it is used: Universal in science, trade and everyday weighing outside the United States.
Milligrams vs Kilograms
The milligram is a metric unit while the kilogram is an SI unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many kilograms are in a milligram?
One milligram equals 1e-06 kilograms.
What is the formula to convert milligrams to kilograms?
Multiply the number of milligrams by 1e-06. To reverse it, divide by 1e-06 instead.
How do I convert kilograms back to milligrams?
Divide by 1e-06, which is the same as multiplying by 1000000.
How many kilograms are in 10 milligrams?
10 mg works out to 1e-05 kg.
How is the milligram defined?
Exactly 1×10⁻⁶ kilogram by SI prefix definition.