Micrograms to Stones
An instant micrograms-to-stones converter, with the formula and a reference table below.
| Micrograms | Stones |
|---|---|
| 1 µg | 1.57473e-10 st |
| 2 µg | 3.14946e-10 st |
| 3 µg | 4.72419e-10 st |
| 5 µg | 7.87365e-10 st |
| 10 µg | 1.57473e-09 st |
| 25 µg | 3.93683e-09 st |
| 50 µg | 7.87365e-09 st |
| 100 µg | 1.57473e-08 st |
How to use
- Enter a value in the Micrograms field.
- The Stones figure appears immediately — no button to press.
- Typing in the Stones field converts back to Micrograms the same way.
- Use the reference table for the values that come up most often.
Micrograms to Stones formula
The factor from micrograms to stones is 1.57473044e-10.
st = µg × 1.57473044e-10
Why this factor: the microgram and the stone are both defined against the kilogram, so dividing one definition by the other gives 1.57473044e-10 directly. Both definitions are set out in full below.
To go the other way, divide by 1.57473044e-10 — or use the Stones to Micrograms converter, which is the same calculation reversed.
Worked example
Start with 2 µg. Multiply by 1.57473044e-10 to get 3.14946e-10 st.
2 µg × 1.57473044e-10 = 3.14946e-10 st
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 stone?
A stone is fourteen pounds, still the customary unit for body weight in Britain and Ireland.
Definition: Fourteen avoirdupois pounds, so exactly 6.35029318 kilograms.
Where it is used: Personal body weight in the UK and Ireland, where weight is usually given as stones and pounds.
Worth knowing: Effectively unused in the United States, where body weight is quoted in pounds alone.
Micrograms vs Stones
The microgram is a metric unit while the stone is an imperial 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 stones are in a microgram?
One microgram equals 1.57473044e-10 stones.
What is the formula to convert micrograms to stones?
Multiply the number of micrograms by 1.57473044e-10. To reverse it, divide by 1.57473044e-10 instead.
How do I convert stones back to micrograms?
Divide by 1.57473044e-10, which is the same as multiplying by 6.35029318e+09.
How many stones are in 10 micrograms?
10 µg works out to 1.57473e-09 st.
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.