Micrograms to Kilograms
Convert micrograms to kilograms instantly — one microgram is 1e-09 kilograms.
| Micrograms | Kilograms |
|---|---|
| 1 µg | 1e-09 kg |
| 2 µg | 2e-09 kg |
| 3 µg | 3e-09 kg |
| 5 µg | 5e-09 kg |
| 10 µg | 1e-08 kg |
| 25 µg | 2.5e-08 kg |
| 50 µg | 5e-08 kg |
| 100 µg | 1e-07 kg |
How to use
- Enter a value in the Micrograms field.
- The Kilograms figure appears immediately — no button to press.
- Typing in the Kilograms field converts back to Micrograms the same way.
- Use the reference table for the values that come up most often.
Micrograms to Kilograms formula
The factor from micrograms to kilograms is 1e-09.
kg = µg × 1e-09
Why this factor: the microgram and the kilogram are both defined against the kilogram, so dividing one definition by the other gives 1e-09 directly. Both definitions are set out in full below.
To go the other way, divide by 1e-09 — or use the Kilograms to Micrograms converter, which is the same calculation reversed.
Worked example
Take 2 µg and multiply by the factor 1e-09: the result is 2e-09 kg.
2 µg × 1e-09 = 2e-09 kg
The converter above does this for any value you type, in either direction.
What is a microgram?
A microgram is one millionth of a gram, used where quantities are vanishingly small but still matter.
Definition: Exactly 1×10⁻⁹ kilogram by SI prefix definition. Symbol µg.
Where it is used: Trace nutrients such as vitamin B12 and folate, hormone doses, and air-quality measurements.
Worth knowing: Sometimes abbreviated 'mcg' on labels specifically to avoid µg being misread as mg — a thousandfold dosing error.
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.
Micrograms vs Kilograms
The microgram 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 microgram?
One microgram equals 1e-09 kilograms.
What is the formula to convert micrograms to kilograms?
Multiply the number of micrograms by 1e-09. To reverse it, divide by 1e-09 instead.
How do I convert kilograms back to micrograms?
Divide by 1e-09, which is the same as multiplying by 1e+09.
How many kilograms are in 10 micrograms?
10 µg works out to 1e-08 kg.
Is there anything to watch out for with micrograms?
Sometimes abbreviated 'mcg' on labels specifically to avoid µg being misread as mg — a thousandfold dosing error.
How is the microgram defined?
Exactly 1×10⁻⁹ kilogram by SI prefix definition. Symbol µg.