Mass and weight
The base unit of mass is the kilogram. In everyday speech we say “weight”, but in physics weight is a force and mass is the amount of matter. The US and UK also use pounds (lb), ounces (oz) and stones (st); precious metals are traded in troy ounces and gemstones are measured in carats.
Handy reference points
1 pound is exactly 0.45359237 kg, 1 ounce is exactly 28.349523125 g and 1 stone is exactly 6.35029318 kg. For quick estimates, 1 kg is about 2.2 pounds and 100 g is about 3.5 ounces. 1 carat is exactly 0.2 grams.
Conversion factors
1 kg = 2.20462 lb
1 lb = 0.453592 kg
One unit converted to all others: Kilogram (kg)
| Unit | Value |
|---|---|
| Milligram (mg) | 1,000,000 |
| Gram (g) | 1,000 |
| Kilogram (kg) | 1 |
| Metric ton (t) | 0.001 |
| Ounce (oz) | 35.274 |
| Pound (lb) | 2.20462 |
| Stone (st) | 0.157473 |
| Microgram (µg) | 1,000,000,000 |
| Carat (ct) | 5,000 |
| Troy ounce (oz t) | 32.1507 |
Common values
| Kilogram (kg) | Pound (lb) |
|---|---|
| 1 kg | 2.20462 lb |
| 5 kg | 11.0231 lb |
| 10 kg | 22.0462 lb |
| 50 kg | 110.231 lb |
| 100 kg | 220.462 lb |
| Pound (lb) | Kilogram (kg) |
|---|---|
| 1 lb | 0.453592 kg |
| 5 lb | 2.26796 kg |
| 10 lb | 4.53592 kg |
| 50 lb | 22.6796 kg |
| 100 lb | 45.3592 kg |