Stone (mass)
From Wikipedia, the free encyclopedia
- For the Chinese unit of mass, see Stone (Chinese mass).
The stone is a unit of mass. It is part of the Imperial system of weights and measures used in the British Isles, and formerly used in most Commonwealth countries. It is equal to 14 pounds and to 6.35029318 kilograms.
Eight stone make a hundredweight in the Imperial system.
When used as the unit of measurement, the plural form of stone is correctly stone (as in, "11 stone"), though stones is sometimes used, not usually by natives of the British Isles. The abbreviation is st. When describing the units, the correct plural is stones (as in, "please enter your weight in stones and pounds").
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[edit] History
The stone was historically used for weighing agricultural commodities. Potatoes, for example, were traditionally sold in stone and half-stone (14-pound and 7-pound) quantities. Historically the number of pounds in a stone varied by commodity, and was not the same in all times and places even for one commodity. The OED contains examples[1] including:
| Commodity | Number of Pounds |
|---|---|
| Wool | 14, 15, 24 |
| Wax | 12 |
| Sugar and spice | 8 |
| Beef and Mutton | 8 |
[edit] Current use
Although no longer an official unit of measure, the stone remains widely used within the British Isles as a means of expressing human body weight. People in these countries normally describe themselves as weighing, for example, "11 stone 4" (11 stone and 4 pounds), rather than "72 kilograms" in most other countries, or "158 pounds" (the conventional way of expressing the same weight in the United States). Its widespread colloquial use may be compared to the persistence in the British Isles of other Imperial units like the foot, the inch, and the mile, despite these having been supplanted entirely or partly by metric units in official use and other contexts. Road distances and speed enforcement area are still expressed officially in yards, miles and miles-per-hour in the United Kingdom. A similar usage persists in Canada, but the Republic of Ireland now uses the metric system. In official use, provision is usually made for the public to express body weight in either stone or kilograms (similar allowance is made for measuring height in feet and inches). For example, on a National Health Service website both metric and Imperial units are used [2].
Outside the British Isles, stone may also be used to express body weight in casual contexts in other Commonwealth countries, particularly Australia.
