How to Convert Kilograms to Pounds (and Pounds to Kilograms)

To convert kilograms to pounds, multiply by 2.20462. To convert pounds to kilograms, multiply by 0.45359237 (or divide by 2.20462). So 70 kg = 154.32 lb and 180 lb = 81.65 kg. For a quick mental estimate, double the kilograms and add 10%: 70 kg → 140 → 154 lb.

The exact conversion factors

The pound is defined from the kilogram, so one direction is exact:

This definition dates from the 1959 international yard and pound agreement among the US, UK, Canada, Australia, New Zealand and South Africa. NIST publishes it as part of the official US conversion factors. For almost all purposes, 2.2046 is accurate enough.

Mental shortcuts

Kilograms to pounds: double it, add 10%

Multiplying by 2.2 is the same as doubling and then adding a tenth of the doubled value:

This uses 2.2 instead of 2.20462, so it runs about 0.2% low: roughly 0.3 lb short on 65 kg, which is usually negligible.

Pounds to kilograms: halve it, subtract 10%

Dividing by 2.2 is close to halving and then taking off a tenth of the half:

This one runs about 0.8% low, because subtracting 10% of the half is equivalent to dividing by 2.22. For a better estimate, multiply by 0.45 instead: 180 × 0.45 = 81, then add a little.

Conversion chart

A metric tonne (1,000 kg) is 2,204.62 lb, slightly more than the US short ton of 2,000 lb. The kg to lbs converter and lbs to kg converter give exact values for any number.

Pounds and ounces

US recipes, newborn weights and package labels often use pounds and ounces, with 16 ounces per pound. Convert to decimal pounds first, then split off the whole pounds:

To go the other way, convert the ounces to a fraction of a pound: 7 lb 8 oz = 7.5 lb, and 7.5 × 0.4536 = 3.40 kg. One ounce is exactly 28.349523125 grams; the grams to ounces converter covers smaller amounts.

Stone

In the UK and Ireland, body weight is often given in stone and pounds. One stone is exactly 14 pounds, or about 6.35 kg.

The stone to kg converter handles the mixed units automatically.

Everyday examples

Gym equipment shows why precision sometimes matters: a “20 kg” plate and a “45 lb” plate look identical but differ by nearly a pound, which adds up on a loaded bar.

How precise do you need to be?

The right number of decimals depends on what the conversion is for.

• Body weight and luggage: one decimal place is plenty. Bathroom scales are rarely more accurate than a few tenths of a pound.
• Cooking: grams are more precise than ounces for baking. Converting a 454 g package to “1 lb” is fine; converting 7 g of yeast to “0.25 oz” is close enough (exact: 0.247 oz).
• Shipping: carriers bill by the pound or kilogram rounded up, so convert precisely and round up at the end, not the start.
• Medicine: doses are usually calculated per kilogram of body weight. Entering a weight in pounds where kilograms are expected more than doubles the dose, which is why many hospitals record patient weight only in kilograms.

Converting in a spreadsheet

Excel and Google Sheets can convert mass directly. =CONVERT(70,"kg","lbm") returns 154.32, and =CONVERT(180,"lbm","kg") returns 81.65. Note the unit code “lbm” for pound-mass; “lbf” is pound-force, a different quantity. For stone, =CONVERT(85,"kg","stone") returns about 13.39, which is 13 stone plus 0.39 × 14 ≈ 5.4 lb.

Common mistakes

• Multiplying when you should divide. Pounds are smaller units, so the pound value is always the larger number, about 2.2 times the kilogram value. If 70 kg comes out as 31.75 lb, you went the wrong way.
• Treating decimal pounds as ounces. 7.5 lb is 7 lb 8 oz, not 7 lb 5 oz.
• Rounding the factor too far. Using 2 instead of 2.2 makes a 100 kg conversion 20 lb short.

Mass, weight and other pounds

Kilograms measure mass; pounds are used for both mass and force. Strictly, a kilogram is the amount of matter, while weight is the force of gravity on it, measured in newtons. A 70 kg person weighs about 686 N on Earth and the same 70 kg on the Moon, where they would weigh about one-sixth as much. In everyday US usage, “pound” means pound-mass, and bathroom scales are calibrated assuming Earth’s gravity. For force calculations, see the weight calculator.

Troy units are different. Precious metals use the troy ounce, 31.1034768 g, about 10% heavier than an ordinary ounce. A troy pound has only 12 troy ounces and weighs 373.24 g. The troy weight converter handles these.

For conversions between any mass units, including grams, tonnes and grains, use the weight and mass converter. Temperature has its own mental shortcuts too; see how to convert Celsius to Fahrenheit.