Convert Pound to Kilogram
Conversion Formula
kg = lb × 0.453592To convert Pound to Kilogram, use the formula above. This is the standard conversion factor used worldwide.
Conversion Table
| Pound (lb) | Kilogram (kg) |
|---|---|
| 1 | 0.453592 |
| 10 | 4.535920 |
| 50 | 22.679600 |
| 100 | 45.359200 |
Why convert Pound to Kilogram
A US traveler checking their luggage against an international airline's kilogram weight limit, or someone filling out a medical or immigration form outside the US that asks for weight in kilograms, starts from the pound figure they already know and needs the metric equivalent. It runs the opposite direction from the more common kilogram to pound lookup, driven by paperwork and limits set by someone else's unit system rather than curiosity about a foreign number.
Where the number comes from
A pound equals exactly 0.45359237 kilograms under the 1959 international agreement, so multiplying a pound figure by that factor gives an exact kilogram result. Most everyday conversions round it to 0.4536 without any meaningful loss of accuracy for luggage, body weight, or shipping purposes.
Quick reference
| 1 lb | 0.4536 kg | exact ratio is 0.45359237 |
| 150 lb | 68.04 kg | a commonly cited adult body weight |
| 50 lb | 22.68 kg | a common US airline checked baggage limit |
| 23 kg | 50.71 lb | a common international checked baggage limit |
| 200 lb | 90.72 kg | |
| 2,000 lb (1 US ton) | 907.18 kg |
Common mistakes
- Airlines often set checked baggage limits at round kilogram figures like 23 kg, and travelers who convert their scale's pound reading with a rough factor, multiplying by 0.45 instead of 0.45359237, can end up believing they're under the limit when they're actually a pound or two over.
- People also forget that US shipping scales frequently default to pounds even when the destination country's customs form requires kilograms, so the conversion has to happen before the form is filled in, not after.
Frequently Asked Questions
Why do airlines set baggage limits in kilograms even for US departures?
International carriers standardize limits across their whole route network in kilograms since most countries they fly to use metric units, so a US departure can still carry a kilogram limit on an international ticket.
How do I check if my luggage is under a 23 kg limit using a US bathroom scale?
Multiply your reading by 0.45359237, or divide the 23 kg limit by that factor to get the pound equivalent, about 50.7 lb, and compare directly against your scale.
Is a US ton the same as a metric tonne?
No. A US short ton is 2,000 lb (907.18 kg), while a metric tonne is 1,000 kg (2,204.6 lb), a meaningfully different figure that matters for freight and shipping quotes.
What's a fast way to estimate pounds to kilograms in my head?
Halve the pound figure, then subtract about 10 percent of that half. It is not exact but lands within a couple percent for a quick gut check.