To convert kilograms to pounds, multiply by 2.20462. To convert pounds to kilograms, multiply by 0.45359237, a factor that is exact because the international pound is defined as precisely 0.45359237 kg. Our free weight converter handles kilograms, grams, milligrams, metric tons, pounds, ounces and stones in one place.
Weight conversion comes up when you read a scale abroad, compare shipping rates, follow a recipe from another country, or log a workout. The rules are simple once you know the factors, and the mistakes people make are predictable. Both are covered below.
Weight conversion factors
Every unit in this table is defined against the kilogram, so you can convert any unit to any other by passing through kilograms.
| Unit | Size in kilograms | Handy equivalent |
|---|---|---|
| Milligram (mg) | 0.000001 | 1/1,000 of a gram |
| Gram (g) | 0.001 | 0.0353 oz |
| Ounce (oz) | 0.028349523 | 28.3495 g |
| Pound (lb) | 0.45359237 | 16 oz |
| Kilogram (kg) | 1 | 2.20462 lb |
| Stone (st) | 6.35029318 | 14 lb |
| Metric ton (t) | 1,000 | 2,204.62 lb |
The weight conversion formula
result = value × (kg per "from" unit) ÷ (kg per "to" unit)
kg → lb: lb = kg ÷ 0.45359237 (or kg × 2.20462)
lb → kg: kg = lb × 0.45359237
g → oz: oz = g ÷ 28.3495
st → kg: kg = st × 6.35029318How to convert kg to lbs and lbs to kg
Kilograms to pounds
Convert 70 kg to pounds: 70 ÷ 0.45359237 = 154.32 lb. To express the decimal part in ounces, multiply it by 16: 0.32 × 16 = 5.2, so 70 kg is about 154 lb 5 oz.
Pounds to kilograms
Convert 180 lb to kilograms: 180 × 0.45359237 = 81.65 kg. For a rough answer in your head, divide pounds by 2.2: 180 ÷ 2.2 = 81.8 kg, which is close enough for conversation but not for a medication dose or a freight invoice.
Grams and ounces in the kitchen
A 250 g block of butter is 250 ÷ 28.3495 = 8.82 oz, and a 1 lb bag of sugar is 453.59 g. These are weight ounces. If a recipe gives cups or fluid ounces, you are dealing with volume, and the weight depends on the ingredient. The cooking converter uses ingredient density to switch between cups and grams, and our guide to precision cooking conversions explains why weighing beats measuring by volume.
Stone, the UK body weight unit
In the UK and Ireland, body weight is often given in stones and pounds. One stone is 14 pounds. To convert 11 st 4 lb to kilograms:
- Convert to pounds: 11 × 14 + 4 = 158 lb.
- Multiply by 0.45359237: 158 × 0.45359237 = 71.67 kg.
Going the other way, 85 kg ÷ 6.35029318 = 13.385 stones. Multiply the decimal by 14 to get pounds: 0.385 × 14 = 5.4, so 85 kg is about 13 st 5 lb.
Which ton is which
The word "ton" covers three different weights, so check which one a document means:
| Ton | Pounds | Kilograms |
|---|---|---|
| Metric ton (tonne) | 2,204.62 | 1,000 |
| US short ton | 2,000 | 907.18 |
| UK long ton | 2,240 | 1,016.05 |
The converter's "Metric Tons" option is the 1,000 kg tonne. For a US short ton, enter 2,000 pounds; for a UK long ton, enter 2,240 pounds.
How to use the Weight Converter
- Open the Weight Converter. It starts on 1 kilogram to pounds, which shows 2.2046.
- Type your number in the Value field. Decimals are accepted; negative weights are not.
- Pick your starting unit in the From list: kilograms, grams, milligrams, metric tons, pounds, ounces or stones.
- Pick the unit you need in the To list.
- Read the Result, rounded to four decimal places. It recalculates as you type.
- Use the swap button between the lists to flip the conversion, for example from kg-to-lb to lb-to-kg.
Mixed values such as 11 st 4 lb or 5 lb 3 oz need to go in as one number in one unit. Convert them to pounds first (158 lb, or 5.1875 lb), then enter that.
Common weight conversion mistakes
- Confusing ounces with fluid ounces. An ounce measures weight; a fluid ounce measures volume. One US fluid ounce of water weighs about 1.04 oz, and for flour, honey or oil the figure is different again.
- Using the wrong ounce for precious metals. Gold and silver are priced in troy ounces of 31.1035 g, about 10% heavier than the standard 28.35 g ounce. The converter uses the standard (avoirdupois) ounce.
- Reading decimal pounds as pounds and ounces. 5.5 lb is 5 lb 8 oz, not 5 lb 5 oz, because a pound has 16 ounces, not 10.
- Rounding 2.20462 to 2.2. On 100 kg, that gives 220 lb instead of 220.46 lb. Fine for a gym chat, not for shipping manifests or anything charged by weight.
- Assuming "ton" means 1,000 kg. A US short ton is about 9% lighter than a metric ton, which matters on freight quotes.
Body weight also feeds into health estimates. The BMI calculator accepts kilograms or pounds, while the water intake calculator asks for body weight in kilograms, so convert pounds first. Our guide to BMI covers what the number means. These tools give estimates, not medical advice.
Frequently asked questions
How many pounds are in a kilogram?
One kilogram equals 2.20462 pounds. For quick mental math, 2.2 is close enough; for anything precise, divide kilograms by 0.45359237.
How do I convert lbs to kg?
Multiply pounds by 0.45359237. For example, 150 lb × 0.45359237 = 68.04 kg. Dividing by 2.2 gives a fast estimate.
How many ounces are in a pound?
There are 16 ounces in a pound. A pound is 453.59 grams and an ounce is 28.35 grams.
How many pounds are in a stone?
One stone is exactly 14 pounds, or about 6.35 kilograms. Stone is mostly used for body weight in the UK and Ireland.
How many grams are in an ounce?
A standard (avoirdupois) ounce is 28.3495 grams. A troy ounce, used for gold and silver, is 31.1035 grams.
Is a kilogram a unit of weight or mass?
Strictly, the kilogram is a unit of mass, while weight is the force gravity exerts on that mass. In everyday use, "weight" in kilograms or pounds means mass, and the conversion factors are the same either way.