About the Weight Converter
This weight converter changes a mass from one unit to another. It covers metric units (milligrams, grams, kilograms and metric tons), US and imperial units (ounces, pounds, stones, US short tons and UK long tons) and carats for gemstones.
Enter a value, pick the two units, and the answer appears with the conversion factor used. A table lists the same weight in every unit, which is useful when you aren't sure which unit a recipe, shipping form or scale is asking for.
How to use it
- Type the number in Value.
- Choose the unit you have in From, such as pounds.
- Choose the unit you want in To, such as kilograms.
- Read the answer and the conversion factor, or check the table for every other unit.
Conversion formula
Each unit is stored as an exact number of kilograms:
result = value × (kg per From unit) ÷ (kg per To unit)
- 1 pound (lb) = 0.45359237 kg exactly
- 1 ounce (oz) = 1/16 lb = 28.349523125 g exactly
- 1 stone (st) = 14 lb = 6.35029318 kg
- 1 US short ton = 2,000 lb = 907.18474 kg
- 1 UK long ton = 2,240 lb = 1,016.0469088 kg
- 1 metric ton (tonne) = 1,000 kg
- 1 carat = 0.2 g = 200 mg
The ounce here is the everyday avoirdupois ounce used for food and parcels. Precious metals are weighed in troy ounces of 31.1034768 g, which this converter does not include.
Common weight conversions
| From | Equals |
|---|---|
| 1 kg | 2.20462 lb |
| 1 lb | 453.59237 g |
| 1 oz | 28.3495 g |
| 100 g | 3.5274 oz |
| 1 stone | 14 lb (6.35 kg) |
| 1 metric ton | 2,204.62 lb |
| 1 long ton | 1.12 short tons |
For quick mental math, halve a weight in pounds and take off a tenth of that to get kilograms: 150 lb → 75 → 67.5 kg (the exact answer is 68.04 kg).
Worked examples
Pounds to kilograms. 150 lb × 0.45359237 = 68.0389 kg.
Stones and pounds to kilograms. In the UK and Ireland, body weight is often given in stones and pounds. For 11 st 7 lb, convert to pounds first: 11 × 14 + 7 = 161 lb. Then 161 × 0.45359237 = 73.03 kg.
Tons. "Ton" means different things in different places. A US short ton is 2,000 lb, a UK long ton is 2,240 lb, and a metric ton (tonne) is 1,000 kg, about 2,204.6 lb. Check which one a document means before converting.
Strictly, these units measure mass, but in everyday use "weight" and "mass" are used interchangeably, and a kitchen or bathroom scale reading in kilograms or pounds converts exactly as shown here. For body weight goals, the BMI calculator accepts pounds or kilograms.
Frequently asked questions
How many pounds are in a kilogram?
1 kilogram is about 2.20462 pounds. To convert kilograms to pounds, divide by 0.45359237, or multiply by 2.20462.
How many ounces are in a pound?
There are 16 ounces in a pound. One ounce is about 28.35 grams.
How many pounds are in a stone?
A stone is 14 pounds, which is about 6.35 kilograms.
What's the difference between a ton and a tonne?
A tonne (metric ton) is 1,000 kg. A US ton is 2,000 lb (907.18 kg) and a UK long ton is 2,240 lb (1,016.05 kg).
How many grams is a carat?
A metric carat is exactly 0.2 grams, so 5 carats is 1 gram. It is used for gemstones, not to be confused with karats for gold purity.
Last updated October 24, 2026. Results are estimates for education and planning — see our disclaimer.