A stone is 14 pounds.
Stones to Milligrams Converter — st to mg
Convert Stone (st) to Milligram (mg) using the exact conversion factor (1 stone = 6,350,293.18 milligram). See the formula, worked examples, conversion table, history, and common uses.
Stones to Milligrams converter
Converter
Mass/Weight Converter
Convert SI mass, imperial weight, jewelry, atomic, and astronomy mass units.
Context values
Some unit families need one extra value for a physically accurate result.
Milligram is 0.001 gram units.
Result = input x 6.35029318 / 1e-6.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Stones to Milligrams
Weight conversions between Stone and Milligram come up constantly in everyday commerce, shipping, and cooking, since US packaging is usually labeled in pounds while most of the rest of the world uses kilograms. Stone is most often used for body weight reporting in the uk and ireland (e.g. '12 stone 5 pounds').
Formula
milligrams = stones × 6350293.18
This factor comes from each unit's defined relationship to the category's base unit: 1 stone equals 6.35029318 base units, and 1 milligram equals 0.000001 base units, so dividing one by the other gives the direct stone-to-milligram factor of 6350293.18.
Simple example
1 st × 6350293.18 = 6,350,293.18 mg
1 stone = 6,350,293.18 milligrams.
Real-world example
50 st × 6350293.18 = 317,514,659 mg
50 stones = 317,514,659 milligrams.
Conversion table
| Stone (st) | Milligram (mg) |
|---|---|
| 1 st | 6,350,293.18 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 |
Reverse conversion: Milligram to Stone
1 mg × 1.57473e-7 = 1.57473e-7 st
1 milligram = 1.57473e-7 stones.
stones = milligrams × 1.57473e-7
For a page dedicated to this direction, see Milligram to Stone.
Understanding the Stone
Stone (st) measures mass. A stone is 14 pounds: exactly 6.35029318 kilograms. It is classified as a UK customary unit.
Where it's used: United Kingdom and Ireland (body weight)
Uses of the Stone today
- Body weight reporting in the UK and Ireland (e.g. '12 stone 5 pounds')
- Historical wool and agricultural produce weighing
History of the Stone
The stone dates to medieval England as a general-purpose weight unit, historically varying by region and commodity (a 'stone' of wool differed from a 'stone' of meat) before settling on 14 pounds for general use. It remains in everyday use for body weight in the UK and Ireland, unlike most other English customary units which have been replaced or supplemented by metric measures.
Historical origin. Stone was not the invention of a single named person; it developed through the process described above.
Understanding the Milligram (mg)
Milligram is 0.001 gram units.
Stone — sources
- UK Weights and Measures Act 1985 — Confirms the stone (14 lb) as a legally recognized UK unit for body weight.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many milligrams are in 1 stone?
1 stone equals 6,350,293.18 milligrams, using the exact defined conversion factor rather than an estimate.
How do I convert stone to milligram?
Multiply the stone value by 6350293.18. The converter above does this instantly to whatever precision you set.
How do I convert milligram back to stone?
Use the reverse factor: 1 milligram equals 1.57473e-7 stones. You can also use the swap control in the converter above to flip the direction instantly.
What is a stone?
Stone (st) measures mass. A stone is 14 pounds: exactly 6.35029318 kilograms. It is classified as a UK customary unit.
What is a milligram?
Milligram (mg) is a unit of mass/weight.
Is the stone to milligram conversion exact?
Yes. A stone is 14 pounds: exactly 6.35029318 kilograms. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the stone still used today?
United Kingdom and Ireland (body weight)