Kilogram is 1000 gram units.
Kilograms to Stones Converter — kg to st
Convert Kilogram (kg) to Stone (st) using the exact conversion factor (1 kilogram = 0.1574730444 stone). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Kilograms to Stones 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.
A stone is 14 pounds.
Result = input x 1 / 6.35029318.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Kilograms to Stones
Weight conversions between Kilogram and Stone 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. Kilogram is typically associated with used as the standard mass unit in nearly every country except the United States and a few others that primarily use the pound., while Stone is typically associated with united Kingdom and Ireland (body weight).
Formula
stones = kilograms × 0.157473044418
This factor comes from each unit's defined relationship to the category's base unit: 1 kilogram equals 1 base unit, and 1 stone equals 6.35029318 base units, so dividing one by the other gives the direct kilogram-to-stone factor of 0.157473044418.
Simple example
1 kg × 0.1574730444 = 0.1574730444 st
1 kilogram = 0.1574730444 stones.
Real-world example
50 kg × 0.1574730444 = 7.873652221 st
50 kilograms = 7.873652221 stones.
Conversion table
| Kilogram (kg) | Stone (st) |
|---|---|
| 1 kg | 0.1574730444 st |
| 5 kg | 0.7873652221 st |
| 10 kg | 1.574730444 st |
| 25 kg | 3.93682611 st |
| 50 kg | 7.873652221 st |
| 100 kg | 15.74730444 st |
Reverse conversion: Stone to Kilogram
0.1574730444 st × 6.35029318 = 0.9999999999 kg
0.1574730444 stones = 0.9999999999 kilograms.
kilograms = stones × 6.35029318
For a page dedicated to this direction, see Stone to Kilogram.
Kilogram vs. Stone
| Aspect | Kilogram | Stone |
|---|---|---|
| Family | SI base unit | UK customary unit |
| Typical use | Pricing and labeling goods sold by weight in retail and commodity trade | Body weight reporting in the UK and Ireland (e.g. '12 stone 5 pounds') |
| Where it's used | Used as the standard mass unit in nearly every country except the United States and a few others that primarily use the pound. | United Kingdom and Ireland (body weight) |
Understanding the Kilogram
Kilogram (kg) measures mass. The kilogram is the SI base unit of mass; every other SI mass unit is a decimal multiple or fraction of it. It is classified as a SI base unit.
Where it's used: Used as the standard mass unit in nearly every country except the United States and a few others that primarily use the pound.
Uses of the Kilogram today
- Pricing and labeling goods sold by weight in retail and commodity trade
- Dosing calculations in medicine, especially for pediatric and weight-based prescriptions
- Structural and material specification in metric-system engineering
- Scientific measurement of mass across chemistry, physics, and materials research
History of the Kilogram
The kilogram's direct predecessor was the 'grave,' defined by the French Academy of Sciences in 1793 as the mass of one cubic decimeter of water at its temperature of maximum density. Because 'grave' echoed the aristocratic title 'graf,' revolutionary France's decree of 18 Germinal, Year III (7 April 1795) renamed the system: the gram became the reference unit, defined as the mass of one cubic centimeter of water at the melting point of ice, and the kilogram — one thousand grams — took over the grave's practical role.
Turning that water-based definition into a physical object required real experimental work: chemist Louis Lefèvre-Gineau was tasked in 1795 with measuring precisely how much a cubic decimeter of water weighed, and former royal jeweller Marc-Étienne Janety then fabricated a platinum cylinder to embody that measured mass. Deposited in the French National Archives in 1799, it became known as the Kilogramme des Archives.
The metric system spread unevenly — Napoleon briefly restricted its use — but France made it compulsory in 1840, and the 1875 Metre Convention (signed by seventeen nations including the US) established the BIPM and a shared international prototype. The platinum-iridium International Prototype of the Kilogram, adopted in 1889 and nicknamed 'Le Grand K,' served as the world's mass reference for over a century.
On 20 May 2019, the kilogram was redefined by fixing the Planck constant at exactly 6.62607015 × 10⁻³⁴ joule-seconds, so it can now be realized in a laboratory (via a Kibble balance) without reference to any physical object.
Historical origin. Kilogram was not the invention of a single named person; it developed through the process described above.
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.
Kilogram — sources
- BIPM — The kilogram (SI base unit) — Official definition and history since the 2019 redefinition.
- NIST — Kilogram: The Past — History of the kilogram standard from the grave to the International Prototype Kilogram.
- SI Brochure, 9th edition (2019), Appendix 2 — BIPM — Official text of the Planck-constant-based definition of the kilogram.
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 stones are in 1 kilogram?
1 kilogram equals 0.1574730444 stones, using the exact defined conversion factor rather than an estimate.
How do I convert kilogram to stone?
Multiply the kilogram value by 0.1574730444. The converter above does this instantly to whatever precision you set.
How do I convert stone back to kilogram?
Use the reverse factor: 1 stone equals 6.35029318 kilograms. You can also use the swap control in the converter above to flip the direction instantly.
What is a kilogram?
Kilogram (kg) measures mass. The kilogram is the SI base unit of mass; every other SI mass unit is a decimal multiple or fraction of it. It is classified as a SI base unit.
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.
Is the kilogram to stone 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 kilogram still used today?
Used as the standard mass unit in nearly every country except the United States and a few others that primarily use the pound.