Weight Converter
Convert kilograms, pounds, ounces, stones and tons with the exact international definitions — instant and private.
| Reference | Exact value |
|---|---|
| 1 pound | 0.45359237 kg |
| 1 ounce | 0.028349523125 kg |
| 1 stone | 6.35029318 kg |
| 1 US ton | 907.18474 kg |
How to use
- Type a weight and pick the from/to units.
- The result updates live as you type.
- Hit ⇅ to swap units and invert the conversion.
Frequently asked questions
Which weight units are supported?
Eight: kilogram, gram, milligram, metric ton, pound, ounce, stone and the US short ton (2,000 pounds). The kilogram is the base unit for all conversions.
How exact is the pound definition?
Since 1959 the international avoirdupois pound has been defined as exactly 0.45359237 kilograms, and the ounce follows as exactly 1/16 of a pound. The tool uses these exact values, so results match any standard reference.
What is a stone and who uses it?
A stone is 14 pounds (6.35029318 kg exactly). It survives mainly in the UK and Ireland for expressing body weight — most other countries switched to kilograms long ago.
What is the difference between metric ton and US ton?
A metric ton is 1,000 kg. A US short ton is 2,000 pounds ≈ 907.185 kg — about 10% lighter. There is also a UK long ton (2,240 lb ≈ 1016.047 kg), which this tool omits as it is nearly obsolete.
Are weight and mass the same thing?
Strictly no — mass measures the amount of matter, weight measures the force gravity exerts on it. In everyday use the units are interchangeable, and this converter follows everyday use.