Stone to Milligrams
Convert stone (st) to milligrams (mg). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.
The Formula
``
milligrams = stone × 6350293.18
stone = milligrams × 1.57473044418e-7
`
One stone is 6,350,293.18 milligrams, and one milligram is 1.5747e-7 stone.
Conversion Table
| Stone | Milligrams |
|---|---|
| 1 st | 6,350,293.18 mg |
| 2 st | 12,700,586.36 mg |
| 5 st | 31,751,465.9 mg |
| 10 st | 63,502,931.8 mg |
| 25 st | 158,757,329.5 mg |
| 50 st | 317,514,659 mg |
| 100 st | 635,029,318 mg |
| 500 st | 3,175,146,590 mg |
| 1,000 st | 6,350,293,180 mg |
The Other Direction
| Milligrams | Stone |
|---|---|
| 1 mg | 1.5747e-7 st |
| 2 mg | 3.1495e-7 st |
| 5 mg | 7.8737e-7 st |
| 10 mg | 1.5747e-6 st |
| 25 mg | 3.9368e-6 st |
| 50 mg | 7.8737e-6 st |
| 100 mg | 1.5747e-5 st |
| 500 mg | 7.8737e-5 st |
| 1,000 mg | 1.5747e-4 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.
Milligrams (mg) — one thousandth of a gram. The metric unit for doses and trace quantities.
A Sense of Scale
British body weight is often given in stone and pounds- An adult is typically 9–14 stone
- A grain of sand is about 1 mg
- An aspirin tablet is 300–500 mg
- Nutrition labels use mg for sodium
Precision
The factor 6350293.18 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.
In Code
`javascript
const stoneToMilligram = (value) => value * 6350293.18;
``
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 | 6350293 | 869,990,141 | — |
| 1 | 6350293.2 | 869,990,168.4 | — |
| 2 | 6350293.18 | 869,990,165.66 | — |
| 3 | 6350293.18 | 869,990,165.66 | — |
| 4 | 6350293.18 | 869,990,165.66 | — |
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 milligrams is only good to three — writing more digits claims precision the measurement never had.