Stone to Tons
Convert stone (st) to tons (t). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.
The Formula
``
tons = stone × 0.00635029318
stone = tons × 157.473044418
`
One stone is 0.00635 tons, and one ton is 157.473 stone.
Conversion Table
| Stone | Tons |
|---|---|
| 1 st | 0.00635 t |
| 2 st | 0.012701 t |
| 5 st | 0.031751 t |
| 10 st | 0.063503 t |
| 25 st | 0.158757 t |
| 50 st | 0.317515 t |
| 100 st | 0.635029 t |
| 500 st | 3.1751 t |
| 1,000 st | 6.3503 t |
The Other Direction
| Tons | Stone |
|---|---|
| 1 t | 157.473 st |
| 2 t | 314.9461 st |
| 5 t | 787.3652 st |
| 10 t | 1,574.73 st |
| 25 t | 3,936.83 st |
| 50 t | 7,873.65 st |
| 100 t | 15,747.3 st |
| 500 t | 78,736.52 st |
| 1,000 t | 157,473.04 st |
What Each Unit Is
Stone (st) — exactly 14 pounds, or 6.35029318 kilograms. A medieval trade weight that varied by commodity until standardised at 14 lb in 1835.
Tons (t) — here the metric tonne: exactly 1,000 kilograms. From the tun, a large wine cask, whose weight became a trade standard.
A Sense of Scale
British body weight is often given in stone and pounds- An adult is typically 9–14 stone
- A small car is about 1.5 t
- A cubic metre of water is 1 t
- Shipping freight is priced per tonne
Precision
The factor 0.00635029318 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.
Watch Out For
- Effectively British-only. US sources give body weight in pounds alone.
- Three different tons exist: metric (1,000 kg), US short (907 kg) and UK long (1,016 kg). This converter uses the metric tonne.
In Code
`javascript
const stoneToTon = (value) => value * 0.00635029318;
``
Where This Conversion Comes Up
- Cooking
- Shipping
- Fitness
- Medicine
- Manufacturing
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 st with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 st becomes | Error |
|---|---|---|---|
| 0 | 0 | 0 | 100.0000% |
| 1 | 0 | 0 | 100.0000% |
| 2 | 0.01 | 1.37 | 57.4730% |
| 3 | 0.006 | 0.822 | 5.5162% |
| 4 | 0.0064 | 0.8768 | 0.7827% |
The right number of significant figures is set by your input, not by the converter. If you measured stone to three significant figures, the answer in tons is only good to three — writing more digits claims precision the measurement never had.