Ounces to Stone
Convert ounces (oz) to stone (st). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.
The Formula
``
stone = ounces × 0.00446428571429
ounces = stone × 224
`
One ounce is 0.004464 stone, and one stone is 224 ounces.
Conversion Table
| Ounces | Stone |
|---|---|
| 1 oz | 0.004464 st |
| 2 oz | 0.008929 st |
| 5 oz | 0.022321 st |
| 10 oz | 0.044643 st |
| 25 oz | 0.111607 st |
| 50 oz | 0.223214 st |
| 100 oz | 0.446429 st |
| 500 oz | 2.2321 st |
| 1,000 oz | 4.4643 st |
The Other Direction
| Stone | Ounces |
|---|---|
| 1 st | 224 oz |
| 2 st | 448 oz |
| 5 st | 1,120 oz |
| 10 st | 2,240 oz |
| 25 st | 5,600 oz |
| 50 st | 11,200 oz |
| 100 st | 22,400 oz |
| 500 st | 112,000 oz |
| 1,000 st | 224,000 oz |
What Each Unit Is
Ounces (oz) — one sixteenth of a pound, or exactly 28.349523125 grams. From uncia, one twelfth — of the Roman libra, before avoirdupois moved it to one sixteenth.
Stone (st) — exactly 14 pounds, or 6.35029318 kilograms. A medieval trade weight that varied by commodity until standardised at 14 lb in 1835.
A Sense of Scale
A slice of bread is about 1 oz- A tennis ball is 2 oz
- US recipes use ounces for dry goods
- British body weight is often given in stone and pounds
- An adult is typically 9–14 stone
Precision
The factor 0.00446428571429 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
- A fluid ounce measures volume, not mass, and the two are only interchangeable for water by coincidence of scale.
- Effectively British-only. US sources give body weight in pounds alone.
In Code
`javascript
const ounceToStone = (value) => value * 0.00446428571429;
``
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 oz with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 oz becomes | Error |
|---|---|---|---|
| 0 | 0 | 0 | 100.0000% |
| 1 | 0 | 0 | 100.0000% |
| 2 | 0 | 0 | 100.0000% |
| 3 | 0.004 | 0.548 | 10.4000% |
| 4 | 0.0045 | 0.6165 | 0.8000% |
The right number of significant figures is set by your input, not by the converter. If you measured ounces to three significant figures, the answer in stone is only good to three — writing more digits claims precision the measurement never had.