Weight Converter
Convert between kilograms, pounds, ounces, stone and more.
Good to know. A pound is exactly 0.45359237 kg. The exact part is the part people forget.
How it works
In plain words
Convert the value into kilograms using the exact size of the unit, then from kilograms into the target unit.
The formula
result = value × (kg per "from" unit) ÷ (kg per "to" unit) 1 lb = 0.45359237 kg · 1 oz = 1/16 lb · 1 st = 14 lb
Worked example
70 kg ÷ 0.45359237 = 154.323584 lb.
Sources
- NIST Special Publication 811, Guide for the Use of the International System of Units, Appendix B Exact conversion factors for US customary units.
- International yard and pound agreement, 1959 1 yard = 0.9144 m and 1 pound = 0.45359237 kg exactly, so 1 inch = 2.54 cm and 1 mile = 1.609344 km.
Sources checked September 29, 2026. 7 automated tests check its answers on every change.
About the weight converter
Kilograms and pounds are the two weights most people need to switch between, whether for body weight, luggage allowances, recipes, parcels or gym plates.
Like the inch, the pound has an exact metric definition: one pound is exactly 0.45359237 kilograms. From that, an ounce is one sixteenth of a pound (about 28.35 g) and a stone, still used for body weight in the UK and Ireland, is 14 pounds (about 6.35 kg).
Watch out for "tons". A metric tonne is 1,000 kg. A US ton (short ton) is 2,000 lb, about 907 kg. A UK ton (long ton) is 2,240 lb, about 1,016 kg. This converter includes the metric tonne and the US ton.
Quick estimates: a kilogram is about 2.2 pounds, so to go from kg to lb, double the number and add 10%. To go from pounds to kilograms, halve it and take off 10%. 100 g is about 3.5 ounces.
Technically, kilograms and pounds measure mass rather than weight, but in everyday life the two are used interchangeably, and on Earth the conversion is the same.
The table below the result shows the value in every unit.
Questions people ask
How many pounds are in a kilogram?
About 2.20462. One pound is exactly 0.45359237 kg.
How do I convert stone to kilograms?
Multiply by 6.35029. 11 stone is about 69.85 kg. One stone is 14 pounds.
How many grams are in an ounce?
About 28.3495 grams.
Is a tonne the same as a ton?
No. A metric tonne is 1,000 kg. A US ton is 907.18 kg and a UK ton is 1,016.05 kg.