How to convert pounds to kilograms
To convert pounds to kilograms, multiply by 0.45359237 (about 0.4536), because one pound is defined as exactly 0.45359237 kilograms. The converter above works in both directions and handles decimals.
For a quick estimate, halve the pounds and take off about 10%: 150 lb → 75 − 7.5 ≈ 68 kg. The exact answer is 68.04 kg.
When you need to convert pounds to kilograms
Kilograms are the standard unit almost everywhere, so people converting from pounds are usually taking a US or UK figure into metric. Common cases:
- Health and medicine: clinics record weight in kilograms and calculate medication doses per kg, so a weight in pounds must be converted first.
- Travel: checking a US weight against an airline’s kilogram baggage allowance.
- Fitness: logging a lift or bodyweight from an imperial programme into a metric tracker.
- Shipping and trade: customs and freight documents that require metric weights.
- Recipes: converting pounds of an ingredient into grams and kilograms for a metric kitchen scale.
Pounds and kilograms: what each unit is
The pound (lb) is the imperial and US customary unit of mass; the international avoirdupois pound equals exactly 0.45359237 kilograms. The kilogram is the base unit of mass in the metric (SI) system. Because the pound is legally defined in terms of the kilogram, the two convert exactly — the only rounding is in how many decimals you display.
Pounds to Kilograms conversion table
| Pounds | Kilograms |
|---|
Common body weights in pounds and kilograms
Body weight is the most common reason for this conversion, so here is a quick reference:
| Pounds | Kilograms |
|---|---|
| 110 lb | 49.9 kg |
| 130 lb | 59.0 kg |
| 150 lb | 68.0 kg |
| 170 lb | 77.1 kg |
| 190 lb | 86.2 kg |
| 220 lb | 99.8 kg |
Worked examples
Convert 150 lb to kg
150 × 0.4536 = 68.04 kg.
Convert 10 lb to kg
10 × 0.4536 = 4.54 kg — about the weight of a large house cat.
Convert 50 lb (a US baggage limit) to kg
50 × 0.4536 = 22.68 kg, just under the common 23 kg checked-bag allowance.
Frequently asked questions
One pound equals exactly 0.45359237 kilograms, usually rounded to 0.4536.
Multiply stone by 14 to get pounds, add the extra pounds, then multiply by 0.4536. 11 st 4 lb = 158 lb = 71.67 kg.
Kilograms are the standard unit for weight in most countries and in medicine, so converting from pounds is common for health and shipping.
Yes. Since the pound is defined as exactly 0.45359237 kg, the conversion is exact; only the displayed decimals are rounded.
200 × 0.4536 = 90.7 kg. A handy landmark: 220 lb is almost exactly 100 kg.