Summary: convert weight between 12 units, free and private
A weight converter changes a mass from one unit to another, such as kilograms to pounds or stones to kilograms. To convert weight for free and privately, type a value, choose the From and To units out of 12 (kilogram, gram, milligram, pound, ounce, tonne, stone, carat, troy ounce, grain, US ton and UK ton), and read the result. It runs in your browser; nothing is uploaded, and the Network tab in DevTools will show that.
The formula is result = value × (From unit in kg ÷ To unit in kg), where each unit is stored as its exact size in kilograms. For example, 150 lb × 0.45359237 = 68.0388555 kg. The All Conversions list shows the same weight in every other unit at once. For length, volume or temperature, use the Unit Converter.
Table of Use: common weight conversions with results
| Situation | Enter and convert | Result |
|---|---|---|
| Body weight in kilograms | 150 lb to kg | 68.0388555 kg |
| Stones and pounds (11 st 4 lb) | 158 lb to kg | 71.66759446 kg |
| Airline baggage allowance | 23 kg to lb | 50.7063203 lb |
| Kitchen scale in ounces | 250 g to oz | 8.818490487 oz |
| Gold quoted per troy ounce | 1 troy oz to g | 31.1034768 g |
| Gemstone size | 5 ct to g | 1 g |
| A metric ton in pounds | 1 t to lb | 2,204.622622 lb |
| A UK long ton in kilograms | 1 UK ton to kg | 1,016.046909 kg |
| Pounds in grains | 1 lb to gr | 7,000 gr |
Features
- 12 units. Metric from milligrams to tonnes, pound, ounce, stone and the US and UK tons, plus carats, troy ounces and grains.
- Exact definitions. 1 lb = 0.45359237 kg, 1 carat = 200 mg and 1 troy ounce = 480 grains (31.1034768 g).
- All Conversions list. One value in every other unit, with a swap button to reverse From and To.
- Copy result. The copy icon saves text such as "150 lb = 68.0388555 kg".
- Common conversions panel for quick rules such as 1 stone = 14 lb.
- Flexible input. 2.5 and 2,5 both work, and so does scientific notation such as 1.5e3. About ten significant digits are shown.
- Plain messages for negative or non-numeric entries and for numbers beyond what a computer can hold.
It converts mass only. To weigh something from its size, find the volume with the Volume Calculator and multiply by the material's density. There is no mixed-unit entry, so type 11 stone 4 pounds as 158 pounds.
How to Use the Weight Converter
- Type the Value. It starts at 1, and zero is allowed.
- Choose From and To. Each dropdown lists the 12 units; the arrows button between them swaps the two.
- Read the result in the highlighted box and copy it if you need it elsewhere.
- Check All Conversions for the same weight in every other unit.
Who Can Use It
- People tracking their health in pounds or stone. The BMI Calculator and Ideal Weight Calculator put a figure in context, and the Percentage Calculator shows a percentage change.
- Cooks following a recipe in ounces or grams. The Calorie Calculator covers daily energy needs.
- Jewellers and bullion buyers working in carats and troy ounces. For prices in another currency, use the Currency Converter.
- Shippers and travellers checking parcel and baggage limits, plus tons and tonnes in freight paperwork.
- Students and DIY builders who also need the Length Converter or Temperature Converter. See the calculators hub for the rest.
Frequently Asked Questions
How many pounds are in a kilogram?
One kilogram is about 2.2046 pounds. The pound is defined as exactly 0.45359237 kg, so to convert kilograms to pounds divide by 0.45359237 (or multiply by about 2.2046), and to convert pounds to kilograms multiply by 0.45359237. For example, 150 lb is 68.0388555 kg.
How do I convert stones and pounds to kilograms?
A stone is exactly 14 pounds, or 6.35029318 kg. Turn the weight into pounds first, then convert: 11 stone 4 pounds is 11 × 14 + 4 = 158 lb, which is 158 × 0.45359237 ≈ 71.67 kg. Enter 158 with From set to Pound and To set to Kilogram.
How do I convert pounds to kilograms in my head?
Halve the pounds, then take away a tenth of that half. For 150 lb, half is 75, a tenth of 75 is 7.5, so the estimate is 67.5 kg. The exact answer is 68.04 kg, so the shortcut lands within about 1%. For anything that matters, such as medicine or shipping charges, use the exact figure.
What's the difference between a ton and a metric ton?
A metric ton (tonne) is exactly 1,000 kg. A US short ton is 2,000 lb (about 907.18 kg) and a UK long ton is 2,240 lb (about 1,016.05 kg). The converter lists all three as separate units, so pick the one your document or supplier uses.
What is a troy ounce?
The troy ounce is the unit used for gold, silver and other precious metals. It is 31.1034768 grams, about 10% heavier than the ordinary (avoirdupois) ounce of 28.349523125 grams. Twelve troy ounces make a troy pound. In the converter it appears as Troy Ounce (oz t).
What is a carat?
The metric carat used for gemstones is exactly 200 milligrams (0.2 g), so a 1.5-carat diamond weighs 0.3 g and 5 carats make 1 g. It is not the same as karat, which describes the purity of gold; 24-karat is pure gold. In the converter, choose Carat (ct).
Is weight the same as mass?
Strictly, kilograms and pounds measure mass, while weight is the force of gravity on that mass, measured in newtons. In everyday use, and on bathroom and kitchen scales, the two words are used interchangeably, which is how this converter uses them.
Is it safe to use an online weight converter?
With this one, yes. The weight converter runs in your browser, so the values you type are not uploaded or stored, and nothing is saved on your device either. You can check the Network tab in your browser's DevTools: converting a weight sends no request.