What Is stone (US)?
The stone US is a unit of weight. It is mostly linked to older British and US use. One stone is the same as 14 pounds, which is a bit more than 6 kilograms. People mainly use it to talk about body weight.
Definition
The stone US is defined using the pound from the US customary and British imperial systems.
- 1 stone US equals exactly 14 pounds avoirdupois
- 1 pound is defined as 0.45359237 kilograms
- So 1 stone US equals 14 × 0.45359237 kilograms
- 1 stone US equals 6.35029318 kilograms
In everyday life, people usually round this to:
- 1 stone US is about 6.35 kilograms
- 1 stone US is 14 pounds
History / Origin
The word stone comes from very old trading habits. Long ago, people used real stones as simple weight standards when selling goods like grain and wool. Over time, different towns and countries chose different stone sizes.
In England and later in Britain, many values were tried, but by the nineteenth century a stone of 14 pounds became common for weighing people and some goods. This 14 pound stone spread to places that used British style measures.
In the United States, the pound became the main unit of weight. The stone was never made an official legal unit for everyday trade. Still, some people used the 14 pound stone informally, so the idea of a stone US is the same as the British stone, just linked to the US definition of the pound.
In 1959, the United States and several other countries agreed on a shared exact value for the pound in kilograms. From that moment, the size of the stone US became fixed and exact through that pound definition.
Symbol & Abbreviation
The stone has a short symbol that is used in many charts and texts.
- Main symbol for stone is st
- When someone wants to be extra clear, they may write st US to show they are using the US pound definition, but this is rare
Examples:
- 9 st means 9 stone
- 9 st 4 lb means 9 stone and 4 pounds
Current Use Around the World
The stone unit is not widely used anymore, but it still appears in some places.
- United States: The stone is not an official unit for trade. Most people use pounds and sometimes kilograms. However, you may see stone used in sports that follow British rules, in old health records, or when people read or watch media from the United Kingdom and Ireland.
- United Kingdom and Ireland: Many people still use stone and pounds to talk about body weight, for example saying My weight is 11 stone 6. Food labels and most trade use kilograms and grams.
- Other countries: Most countries now use the metric system. There the kilogram is the main unit, and stone is only seen in foreign books, movies, or sports reports.
So, stone US is mostly a way to understand or convert numbers you see in older or British based sources rather than a unit you will use in shops in the United States.
Example Conversions
Here are some simple conversion facts.
- 1 stone US equals 14 pounds
- 1 stone US equals about 6.35 kilograms
- 0.5 stone US equals 7 pounds, about 3.18 kilograms
- 2 stone US equals 28 pounds, about 12.70 kilograms
To convert from stone US to pounds:
- Multiply the number of stone by 14
- Example: 8 st × 14 equals 112 lb
To convert from pounds to stone US:
- Divide the number of pounds by 14
- Example: 175 lb ÷ 14 equals 12.5 st
To convert from stone US to kilograms:
- Multiply the number of stone by 6.35029318
- For easy mental maths, you can multiply by 6.35 and accept a tiny rounding difference
- Example: 10 st × 6.35 is about 63.5 kg
To convert from kilograms to stone US:
- Divide the number of kilograms by about 6.35
- Example: 70 kg ÷ 6.35 is about 11.0 st
Related Units
The stone US is closely linked to these other weight units.
- Pound lb: The base unit used to define the stone. 1 stone US equals 14 pounds.
- Ounce oz: A smaller unit used in US customary and British imperial systems. 1 pound equals 16 ounces, so 1 stone US equals 224 ounces.
- Kilogram kg: The main metric unit of mass. 1 stone US equals about 6.35 kilograms.
- Gram g: A small metric unit. 1 kilogram equals 1000 grams, so 1 stone US equals about 6350 grams.
- US ton short ton: A large weight unit. 1 short ton equals 2000 pounds. Since 1 stone US equals 14 pounds, 1 short ton equals about 142.857 stone US.
FAQs
What is a stone US in simple words
A stone US is a way to measure weight. It is the same as 14 pounds, which is a bit more than 6 kilograms.
How many pounds are in 1 stone US
There are exactly 14 pounds in 1 stone US.
How many kilograms are in 1 stone US
1 stone US equals 6.35029318 kilograms. For most everyday use, you can say 1 stone is about 6.35 kilograms.
Is stone an official unit in the United States
No. The stone is not an official trading unit in the United States. Shops and laws use pounds, ounces, and tons, and sometimes kilograms. The stone only appears in special or older contexts.
Why do I see people in the UK give their weight in stone and pounds
In the United Kingdom and Ireland, many people are used to saying body weight in stone and pounds, such as 10 stone 3. It is part of everyday speech, even though official systems are now metric.
What is the difference between stone US and stone UK
In practice, there is no size difference. Both are 14 pounds. The name stone US just shows that the value is tied to the US pound definition, which is now the same as the modern international pound used in the UK.
Should I use stone US for science or school work
No. For science, engineering, and most school work, you should use kilograms and grams. Stone US is useful only to understand or convert older or British style weight values.
How can I quickly estimate stone from pounds in my head
Divide the pounds by 14. For example, if someone weighs 196 pounds, do 196 ÷ 14 to get 14 stone.
How can I quickly estimate stone from kilograms in my head
Divide the kilograms by about 6.5 to get a rough idea. For example, 65 kg is about 10 stone because 65 ÷ 6.5 equals 10. This gives a close estimate.
