Milligrams to Stones Converter
Convert Milligrams (mg) to Stones (st) instantly, or use the conversion table below to look up common values.
Milligrams to Stones conversion table
| Milligrams (mg) | Stones (st) |
|---|---|
| 1 | 1.5747e-7 |
| 2 | 3.1495e-7 |
| 3 | 4.7242e-7 |
| 4 | 6.2989e-7 |
| 5 | 7.8737e-7 |
| 10 | 1.5747e-6 |
| 25 | 3.9368e-6 |
| 50 | 7.8737e-6 |
| 100 | 1.5747e-5 |
How to convert Milligrams to Stones
1 mg equals 1.5747e-7 st. Use the converter above for any value, or read the table for common conversions.
st = mg × 1.5747304441776967e-7 · mg = st × 6350293.180000001Multiply a milligrams figure by 1.5747e-7 to get stones, or divide it by 6,350,293.18 to go the other way.
Worked examples
- 1 mg= 1.5747e-7 st
- 5 mg= 7.8737e-7 st
- 10 mg= 1.5747e-6 st
- 25 mg= 3.9368e-6 st
- 100 mg= 1.5747e-5 st
What these units are
Milligrams (mg). A milligram is one thousandth of a gram. It is used for medicine doses, laboratory work, water-quality readings and any measurement of trace amounts.
Stones (st). A stone is exactly 14 pounds, or 6.35029318 kilograms. It is used almost exclusively in the UK and Ireland, mainly for body weight.
Metric conversions are exact. Results are displayed rounded, so values at the extreme ends of the scale — milligrams and tonnes — carry fewer significant digits than the middle of the range.
Converting Milligrams to Stones in practice
Reading the result in stones
A stone is exactly 14 pounds, which equals 6.35029318 kilograms, or 6,350.29318 grams. It is a body-weight unit used in the United Kingdom and Ireland, not part of the metric system.
Stones are used almost exclusively for adult body weight, and they appear on bathroom scales and in medical records in the United Kingdom and Ireland. Produce and freight are never sold by the stone.
The stone is exact by definition at 14 pounds, and the kilogram figure follows from the exact pound. Because results are rounded for display, a stone to kilogram round trip can differ in the last digit.
Reading a stone figure as pounds is the common error: a scale showing 12 stone has measured 168 pounds, not 12. Stones are conventional for body weight, while kilograms serve medical dosing and trade.
Stones sit between pounds and kilograms in size, and mixing them up causes large errors: a stone value is 14 times its pound value and 6.35029318 times its kilogram value. Metric records therefore avoid stones.
Checking a milligrams to stones conversion
Between the metric units a weight conversion is a power of a thousand, so grams to kilograms and kilograms to tonnes are decimal shifts. The imperial units are all defined against the kilogram, which makes every metric-to-imperial pair a multiplication with the same factor at any size.
The dimension where this goes wrong is the ounce, because the same word covers two different weights. An avoirdupois ounce is one sixteenth of a pound and is the one used for food and parcels; a troy ounce is about 10% heavier (31.1035 g) and is used for precious metals. A price per ounce is meaningless until you know which ounce is meant.
To check a weight conversion, convert the result back, or go through the pound or the kilogram as a middle step. The commonest error is converting a figure stated in pounds into kilograms and then comparing it with a figure that was already in kilograms, which doubles or halves nothing and merely hides the mistake.
Tanzania reference points
Real quantities, converted into the units on this page.
The most a packet declared between 500 g and 1 kg may fall short under Tanzanian weights and measures rules
15 g = 15,000 mg = 0.002362 st
Table IIIC of the 2019 regulations allows an individual deficiency of 1.5%, or 15 g, on a nominal net content between 500 g and 1 kg. Regulation 179 separately requires the average net content of a whole lot to be at least what the packet declares, so the tolerance is on single packets rather than the batch.
Source: The Weights and Measures (General) Regulations, 2019 (GN No. 288) — Weights and Measures Agency · verified 2026-09-14
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