How to use the weight Converter
- Enter the value.
- Choose the from from the list.
- Choose the to from the list.
- The result updates instantly as you type. There is no button to press.
- Use Copy result to copy the figures, or Copy link to share a link that reopens the weight Converter with the same inputs.
How it works
Strictly speaking, kilograms and pounds measure mass, the amount of matter in something, while weight is the force of gravity on that mass. In everyday life the two words mean the same thing, and this converter handles all the common units for body weight, cooking, shipping, precious metals and gemstones.
The pound is defined as exactly 0.45359237 kilograms (since 1959), and the other imperial units follow from it. There are 16 ounces in a pound and 14 pounds in a stone, a unit still widely used for body weight in the UK and Ireland. "Ton" is a trap: a US short ton is 2,000 lb (907.18 kg), a UK long ton is 2,240 lb (1,016.05 kg), and a metric tonne is 1,000 kg.
Gold, silver and platinum are priced in troy ounces of 31.1035 g, about 10% heavier than the ordinary (avoirdupois) ounce of 28.3495 g. Gemstones use the metric carat, exactly 200 mg. For body weights, the converter also shows the result as pounds and ounces and as stone and pounds.
Formula
Example
70 kg ÷ 0.45359237 = 154.32 lb, which is 154 lb 5.2 oz, or 11 st 0.3 lb. Going the other way, a 10-pound bag of flour is 10 × 0.45359 = 4.54 kg, and a 1-troy-ounce gold coin weighs 31.10 g, about 1.097 ordinary ounces.
Frequently asked questions
How do I convert kg to lbs in my head?
Double the kilograms and add 10%. 70 kg → 140 + 14 = 154 lb. To go from pounds to kilograms, halve and subtract 10%.
How many pounds are in a stone?
14 pounds, or about 6.35 kg. A person weighing 11 stone 4 pounds weighs 158 pounds (71.7 kg).
Is a troy ounce the same as an ounce?
No. A troy ounce, used for precious metals, is 31.1035 g. A standard ounce is 28.3495 g, so a troy ounce is about 9.7% heavier.