Home / Weight and Mass Conversion / Convert Stone (US) to Kilogram

# Convert Stone (US) to Kilogram

Please provide values below to convert stone (US) to kilogram [kg], or vice versa.

 From: stone (US) To: kilogram

### Stone

Definition: A stone (symbol: st) is an English and imperial unit of mass. It is defined as 14 pounds or 6.35029318 kilograms.

History/origin: The name "stone" is derived from the use of stones as weights since antiquity. Standardized stones were historically used for trade in England as well as some countries in northern Europe. In England, the stone had multiple definitions throughout history, based on the commodity and on local standards. In 1350, the stone was standardized to be used for wool at a weight of 14 pounds, and in 1835, the United Kingdom adopted this definition for use in the imperial system.

Current use: The stone as a unit of mass is used mostly in the United Kingdom for measuring body weight. Most other countries measure body weight in kilograms, and in some cases, in pounds.

### Kilogram

Definition: A kilogram (symbol: kg) is the base unit of mass in the International System of Units (SI). It is currently defined as being equal to the mass of the International Prototype of the Kilogram (IPK), a cylinder made of a platinum-iridium alloy.

History/origin: The name kilogram was derived from the French "kilogramme," which in turn came from adding Greek terminology meaning "a thousand," before the Late Latin term "gramma" meaning "a small weight."

Unlike the other SI base units, the kilogram is the only SI base unit with an SI prefix. SI is a system based on the meter-kilogram-second system of units rather than a centimeter-gram-second system. This is at least in part due to the inconsistencies and lack of coherence that can arise through use of centimeter-gram-second systems, such as those between the systems of electrostatic and electromagnetic units.

The kilogram was originally defined as the mass of one liter of water at its freezing point in 1794, but was eventually re-defined, since measuring the mass of a volume of water was imprecise and cumbersome. The current definition of a kilogram, defined as being equal to the mass of a physical prototype, is still imperfect. This is evidenced by the fact that the mass of the original prototype for the kilogram now weighs 50 micrograms less than other copies of the standard kilogram.

Current use: As a base unit of SI, the kilogram is used globally in all fields and applications, with the exception of countries like the United States, where the kilogram is used in many areas, at least to some extent (such as science, industry, government, and the military) but typically not in everyday applications.

Possible future changes: The definition of some SI base units may change in the near future. The International Committee for Weights and Measures (CIPM) has proposed re-definition of some of the SI base units in an attempt to further improve the system. Although the definitions of some units may change, the actual size of the units would remain the same; the change in definition will not have much, if any, effect on the daily use of these units.

The kilogram is one of the SI units being considered for re-definition. The current definition is based on the mass of a physical prototype which has been seen to change over time. Although the measured change is relatively small (50 micrograms), having a standard of measurement that changes at all is undesirable. As such, the proposed re-definition of the kilogram seeks to make the kilogram a measurement based on a constant of nature, rather than a physical standard that is subject to change.

If the formal vote to change the definition passes, the kilogram will instead be based on Planck's constant. This change would tie the definition of the kilogram to that of the second and the meter. Even though this would change the definition of the kilogram, the actual size of the unit will remain the same. The proposed changes are intended to improve the definitions of SI base units, not to actually change how the units are used throughout the world.

### Stone (US) to Kilogram Conversion Table

Stone (US)Kilogram [kg]
0.01 stone (US)0.0566990463 kg
0.1 stone (US)0.5669904625 kg
1 stone (US)5.669904625 kg
2 stone (US)11.33980925 kg
3 stone (US)17.009713875 kg
5 stone (US)28.349523125 kg
10 stone (US)56.69904625 kg
20 stone (US)113.3980925 kg
50 stone (US)283.49523125 kg
100 stone (US)566.9904625 kg
1000 stone (US)5669.904625 kg

### How to Convert Stone (US) to Kilogram

1 stone (US) = 5.669904625 kg
1 kg = 0.1763698097 stone (US)

Example: convert 15 stone (US) to kg:
15 stone (US) = 15 × 5.669904625 kg = 85.048569375 kg