Pound to Kilogram Converter
Weight · unit-converter
Convert Pound to Kilogram with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations use gram-based factors (international avoirdupois pound and metric definitions). The full Weight Converter also includes carat, grain, and US/UK hundredweight.
Calculator
From: Pound (lb)
To: Kilogram (kg)
About Pound
The international avoirdupois pound is exactly 0.45359237 kg. It is the standard pound for weight in the US and for many trade weights.
About Kilogram
The kilogram is the SI base unit of mass (defined via fundamental constants). Everyday metric weights and science use kilograms and grams.
How to convert pounds to kilograms
1 pound is equal to 0.45359237 kilogram:
1 lb = (453.59237 g ÷ 1000 g) kg = 0.45359237 kg
Each pound is defined as 453.59237 g and each kilogram as 1000 g, so one lb equals 453.59237 ÷ 1000 kg = 0.45359237 kg.
Let w(lb) be the numeric value of the same mass measured in Pound (lb), and w(kg) the value in Kilogram (kg). Then:
w(kg) = w(lb) × (453.59237 / 1000)
Equivalently, divide by how many lb fit into one kg (grams per kg divided by grams per lb):
w(kg) = w(lb) ÷ 2.20462262184878
Or: kilogram = pound ÷ 2.20462262184878
Examples
Example #1: Convert 20 lb to kilogram
20 lb = 20 lb × (453.59237/1000) kg = 9.0718474 kg
20 lb = 20 lb ÷ 2.20462262184878 = 9.0718474 kg
Example #2: Convert 50 lb to kilogram
50 lb = 50 lb × (453.59237/1000) kg = 22.6796185 kg
50 lb = 50 lb ÷ 2.20462262184878 = 22.6796185 kg
Summary
To convert Pound to Kilogram, multiply the value in lb by the ratio of grams per lb divided by grams per kg. Equivalently: value_kg = value_lb × (453.59237 / 1000). Numerically, 1 lb equals 0.45359237 kg.
Relationship context
You are converting between imperial / UK (stone, long ton, pound, ounce) (Pounds) and metric (SI) (Kilograms). Metric mass is decimal from the gram; US and imperial masses use pounds and ounces with fixed definitions relative to the kilogram. The numeric factor used here is 4.535924e-1.
Conversion tables
| Pound (lb) | Kilogram (kg) |
|---|---|
| 0.1 | 0.045359237 |
| 1 | 0.45359237 |
| 2 | 0.90718474 |
| 3 | 1.36077711 |
| 4 | 1.81436948 |
| 5 | 2.26796185 |
| 6 | 2.72155422 |
| 7 | 3.17514659 |
| 8 | 3.62873896 |
| 9 | 4.08233133 |
| Pound (lb) | Kilogram (kg) |
|---|---|
| 10 | 4.5359237 |
| 20 | 9.0718474 |
| 30 | 13.6077711 |
| 40 | 18.1436948 |
| 50 | 22.6796185 |
| 60 | 27.2155422 |
| 70 | 31.7514659 |
| 80 | 36.2873896 |
| 90 | 40.8233133 |
| 100 | 45.359237 |