The stone is an imperial unit of mass equal to 14 pounds or approximately 6.3503 kilograms.
Definition & Scientific Metrology
The stone is still widely utilized in everyday speech across the United Kingdom and Republic of Ireland to describe human body weight.
6.35029318 kgOrigins & Historical Evolution
Originally dating back to antiquity when actual stones were used on counterbalance scales. King Edward III standardized the trade stone to 14 lbs in 1350.
1 Stone in Other Mass Units
Direct standard conversion equivalents for 1 st:
| Target Unit | Equivalent Value | Multiplier Equation |
|---|---|---|
| Pounds (lbs) | 14 | 1 st × 14 |
| Kilograms (kg) | 6.35 | 1 st × 6.35029318 |
| Grams (g) | 6,350.293 | 1 st × 6350.293 |
| Ounces (oz) | 224 | 1 st × 224 |
Common Real-World Applications
- Human body weight in the UK and Ireland
- Boxing and horse racing jockeys in Great Britain
Interesting Metrology Facts
If someone in London says they weigh "11 stone 4", that translates to 11 × 14 + 4 = 158 pounds (71.6 kg).
The stone was formally prohibited for commercial trade use in the UK in 1985, but remains ubiquitous in culture.
Measurement Standards & Accuracy
Standard MultipliersFactors based on the 1959 International Yard and Pound Agreement and NIST SP 811.
- BIPM International Metrology Treaty
- NIST Guide for SI Units
- ISO 80000-4 Quantities and Units — Mass
Related Tools & Resources for Stone
Discover calculation widgets, unit comparisons, and printable lookup sheets for st: