Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Stone to Kilograms
Convert st to kg instantly, then review the formula, assumptions, and rounding guidance.
Weight & massInstant result
Decimals
Formula result = input × 6.35029318 ÷ 1. 1 st = 6.3503 kg
Common examples
One value, several units
Kilograms6.3503 kg
Grams6,350.2932 g
Milligrams6,350,293.18 mg
Metric tonnes0.0064 t
Pounds14 lb
Ounces224 oz
Conversion table
| st | kg |
|---|---|
| 1 st | 6.3503 kg |
| 2 st | 12.7006 kg |
| 5 st | 31.7515 kg |
| 10 st | 63.5029 kg |
| 25 st | 158.7573 kg |
| 50 st | 317.5147 kg |
| 100 st | 635.0293 kg |
Conversion chart
1 st6.3503 kg
5 st31.7515 kg
10 st63.5029 kg
25 st158.7573 kg
50 st317.5147 kg
Worked example
1 kilogram equals 2.20462 pounds.
Unit definition
Stone (st) One stone equals 6.35029318 kilogram.
Unit history
Stone is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert st to kilogram.
3. Convert the base value to kg and apply your display precision.
Understand the result before using it
Stone to Kilograms converts a value measured in Stone (st) into the equivalent value in Kilograms (kg). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 6.35029318 ÷ 1
Assumptions
- Stone and Kilograms represent the same weight & mass quantity.
- The input is expressed in st; the output is expressed in kg.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 st = 6.35029318 kg. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a st measurement in a document that expects kg.
- Compare a stone value with a value reported in kilograms.
- Check the st-to-kg arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Everyday language often says weight, but these units represent mass. Force requires a local gravitational acceleration.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Stone to Kilograms?
result = input × 6.35029318 ÷ 1 Using the displayed relationship, 1 st equals 6.35029318 kg.
How many Kilograms are in one Stone?
One Stone is 6.35029318 Kilograms. The displayed digits may be rounded.
Can I reverse the st to kg conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts kg back to st.
Is the Stone to Kilograms result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.