Weight Converter
Convert kilograms, grams and tonnes to pounds, ounces, stone and tons — with the exact international pound (0.45359237 kg) behind every result. Results update as you type; exact factors shown.
One stone is 6.3503 kilograms — see the exact factor, not a rounded rule of thumb.
How the weight converter works
Mass converts through the kilogram. The avoirdupois pound has been exactly 0.45359237 kg since 1959, so an ounce is 28.349523125 g and a stone (14 lb) is 6.35029318 kg. A US short ton is 2,000 lb; an imperial long ton is 2,240 lb; a metric tonne is 1,000 kg.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common mass conversions
| From | To | Units |
|---|---|---|
| 1 kg | 2.2046 lb | kilogram to pounds |
| 1 lb | 0.4536 kg | pound to kilograms |
| 1 st | 6.3503 kg | stone to kilograms |
| 1 oz | 28.3495 g | ounce to grams |
| 100 g | 3.5274 oz | grams to ounces |
| 1 t | 2,204.6226 lb | tonne (metric ton) to pounds |
| 1 US ton | 907.1847 kg | US ton (short) to kilograms |
| 1 long ton | 1,016.0469 kg | imperial ton (long) to kilograms |
| 10 st | 140 lb | stones to pounds |
| 70 kg | 11.0231 st | kilograms to stones |
Units in this converter and their exact factors
| Unit | Symbol | One unit in kilograms |
|---|---|---|
| milligram | mg | 0.000001 kilogram |
| gram | g | 0.001 kilogram |
| kilogram | kg | 1 kilogram |
| tonne (metric ton) | t | 1,000 kilogram |
| ounce | oz | 0.0283495231 kilogram |
| pound | lb | 0.45359237 kilogram |
| stone | st | 6.35029318 kilogram |
| US ton (short) | US ton | 907.18474 kilogram |
| imperial ton (long) | long ton | 1,016.0469088 kilogram |
FAQFrequently asked questions about mass conversion
How many pounds are in a kilogram?
About 2.2046 pounds. Exactly, 1 kg = 1 / 0.45359237 lb.
How many pounds are in a stone?
Exactly 14 pounds, or 6.35 kg. Stone is still used for body weight in the UK and Ireland.
What is the difference between a ton and a tonne?
A metric tonne is 1,000 kg. A US (short) ton is 2,000 lb = 907.2 kg; an imperial (long) ton is 2,240 lb = 1,016 kg.
How many grams are in an ounce?
28.35 g. Note that a troy ounce, used for precious metals, is 31.1035 g and is not included here.
Is weight the same as mass?
In everyday use yes; strictly, these units measure mass and weight is the force gravity exerts on it. The conversions are the same either way.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.