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 microgram (mcg) is a metric unit of mass equal to one-millionth of a gram. It’s one of the smallest standard units of mass, commonly used in medical, nutritional, and scientific settings where extremely small quantities matter.
The term comes from the Greek word mikros meaning “small” and “gram,” the base metric unit for mass. Its official SI symbol is µg. However, in medical practice especially in the U.S. mcg is used to prevent confusion with mg (milligram), which is 1,000 times larger.
How Is Microgram Used?
1 st = 6,350,293,180 µg
Let’s say you want to convert 100 st to µg.
Using the formula:
100 × 6,350,293,180 = 635,029,318,000 µg
So, 100 st is approximately 635,029,318,000 µg.
| Stone (st) | Microgram (µg) |
|---|---|
| 1 st | 6,350,293,180 µg |
| 2 st | 12,700,586,360 µg |
| 3 st | 19,050,879,540 µg |
| 4 st | 25,401,172,720 µg |
| 5 st | 31,751,465,900 µg |
| 6 st | 38,101,759,080 µg |
| 7 st | 44,452,052,260 µg |
| 8 st | 50,802,345,440 µg |
| 9 st | 57,152,638,620 µg |
| 10 st | 63,502,931,800 µg |
| 11 st | 69,853,224,980 µg |
| 12 st | 76,203,518,160 µg |
| 13 st | 82,553,811,340 µg |
| 14 st | 88,904,104,520 µg |
| 15 st | 95,254,397,700 µg |