A stone is a unit of weight used primarily in the United Kingdom and Ireland to measure body weight. One stone equals 14 pounds or approx. 6.35 kilograms. It's not part of the official metric or imperial systems, but it remains a widely recognized standard in health, fitness, and everyday conversation in the UK. If someone says they weigh "11 stone," they mean 154 pounds (11 × 14).
The stone has historical roots going back to ancient Europe, where stones of specific weight were used in trade. Over time, England standardized the stone to mean 14 pounds in 1835, and that value is still used today. While most countries have adopted the metric system, the stone remains part of British culture—primarily when referring to personal weight.
How is the Stone Used: The stone is most commonly used to express body weight in the UK and Ireland. You'll often hear weights given in stone and pounds together, like "11 stone 4 pounds" instead of 158 pounds or 71.6 kg. It's rarely used in scientific, industrial, or commercial applications today. The metric system has replaced it in those contexts.
A kilogram, abbreviated as kg, is the standard unit of mass in the metric system used in nearly every country in the world. Whether you're weighing yourself at the gym, buying fruits at the grocery store, or measuring ingredients in a recipe, chances are you're using kilograms, especially if you're outside the U.S.
The term "kilogram" comes from French, combining kilo (meaning "a thousand") with gram. One kilogram equals 1,000 grams. Originally, the kilogram was defined by a physical object a platinum-iridium cylinder stored in France. But since 2019, scientists now define it using fundamental constants of nature like the Planck constant, making it far more precise and stable for scientific use.
How the Kilogram Is Used:The kilogram is part of everyday life in countries using the metric system:
1 st = 6.350293 kg
Let’s say you want to convert 12 st to kg.
Using the formula:
12 × 6.350293 = 76.204 kg
So, 12 st is approximately 76.204 kg.
| Stone (st) | Kilogram (kg) |
|---|---|
| 1 st | 6.35 kg |
| 2 st | 12.701 kg |
| 3 st | 19.051 kg |
| 4 st | 25.401 kg |
| 5 st | 31.751 kg |
| 6 st | 38.102 kg |
| 7 st | 44.452 kg |
| 8 st | 50.802 kg |
| 9 st | 57.153 kg |
| 10 st | 63.503 kg |
| 11 st | 69.853 kg |
| 12 st | 76.204 kg |
| 13 st | 82.554 kg |
| 14 st | 88.904 kg |
| 15 st | 95.254 kg |