LBS to KG converter, pounds to kilograms.

To convert lbs to kg, multiply the pounds by 0.45359237. So 1 lb is 0.45359 kg, 150 lbs is 68.03886 kg and 200 lbs is 90.71847 kg. Unlike the other direction, this factor is the exact definition of the pound, so no rounding is hidden in the factor itself. Only the last digit you read is rounded.

How to use the converter

1. Type a weight in the Pounds (lb) box, such as 150. The big result shows kilograms.
2. Weights written as pounds and ounces need one extra step: type the ounces as a decimal pound. 8 lbs 12 oz is 8.75 lbs, because 12 ÷ 16 = 0.75.
3. Use Decimals to set the places. For a body weight, 1 decimal is usually enough.
4. Click a value in Common values to load it into the box, then press Copy result or Copy link.
5. Press Print chart for a one page pounds to kilograms chart.

The definition, and why it is exact

The pound is the defined unit and the kilogram is the thing it is fixed against. NIST Handbook 44 (2026), Appendix C lists 1 avoirdupois pound as 0.453 592 37 kilograms and 1 avoirdupois ounce as 28.349 523 125 grams. NIST Special Publication 811, Appendix B.8 gives the same pound as 0.4535924, rounded to seven digits. Both were checked 18 Oct 2026. This converter uses the full 0.45359237, which has eight decimals and ends there, so lbs to kg can be written down exactly. The other way round, kg to lbs, never ends, which is why the KG to LBS converter page rounds more.

A shortcut for the head

Halve the pounds, then take away a tenth of the half. For 150 lbs: half is 75, a tenth of 75 is 7.5, and 75 − 7.5 = 67.5 kg. The exact answer is 68.03886 kg. The shortcut uses 0.45 instead of 0.45359, so it runs 0.79 percent low, which is 0.54 kg here. If you want it closer, divide by 2.2 instead: 150 ÷ 2.2 is 68.18, only 0.14 kg high.

Worked examples

• A body weight of 150 lbs. 150 × 0.45359237 = 68.03886 kg. Rounded to one place that is 68 kg.
• A 25 lb dumbbell. 25 × 0.45359237 = 11.33981 kg. A 45 lb plate is 20.41166 kg, so a pair on a bar adds 40.82331 kg.
• A baby born at 7 lbs 8 oz. 8 oz is 0.5 lb, so the weight is 7.5 lbs. 7.5 × 0.45359237 = 3.40194 kg, or 3.4 kg to two places.
• A bag of flour sold at 5 lbs. 5 × 0.45359237 = 2.26796 kg, which is 2,268 g.

Pounds as mass, and pounds as force

The pound in a recipe or on a scale is a unit of mass. There is also a pound-force, abbreviated lbf, which is a push. One pound-force is the weight of one pound of mass under standard gravity, which is 0.45359237 × 9.80665 = 4.4482216152605 newtons. If a tyre gauge, a wrench or a spec sheet says lbf, lbf·ft or psi, it is not asking for kilograms. Convert it to newtons or use the unit converter. For a weight on a scale, the lbs to kg answer is the right one.

Common gym and shop weights in kilograms

Weights that are sold in pounds often have a metric twin that is close but not equal. The table shows the exact kilogram value of some common pound weights, so you can compare them with a metric set.

A 45 lb plate is 20.412 kg, which is not the 20 kg a metric plate set uses. A mixed set of plates adds up to something that is correct in neither system, so check the number stamped on the plate, not the number you expected. A 100 lb weight is 45.359 kg, so 100 lbs is a little over 45 kilos.

Pounds and ounces to kilograms in one go

Lots of US weights are written as pounds and ounces, such as a baby at 8 lbs 6 oz, or a parcel at 3 lbs 11 oz. The shortest way is to turn the whole thing into ounces, multiply by 28.349523125 and divide by 1,000 for kilograms. For 8 lbs 6 oz: 8 × 16 + 6 = 134 oz, and 134 × 28.349523125 = 3,798.84 g, which is 3.799 kg. Or turn the ounces into a decimal pound first: 6 ÷ 16 = 0.375, so 8.375 lbs, and 8.375 × 0.45359237 = 3.799 kg. The two routes agree, because the converter works on exact fractions.

Who uses lbs to kg, and why

Americans giving a weight to a doctor, a trainer or a foreign airline. Cooks using a metric recipe with a pound of meat. People buying from a site that lists kilograms. Lifters working out loads in kilograms for a competition. The real cost of a bad conversion is small for a body weight and larger for a drug dose, a parcel or a shipping quote, so use the exact factor and not 0.45 when the number matters. For ounces and grams use the Grams to ounces converter.