Turn pounds into kilograms in an instant.
Type a weight in pounds and read the exact kilograms as you go, or type kilograms to convert the other way. Copy the result in one click and see grams, ounces and stone at a glance.
Your weight
Edit either field and the other updates live. 1 lb = 0.45359237 kg.
What this means
Common pound values in kilograms
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Pounds and kilograms explained
The Pound-to-Kilogram Conversion Factor
One pound equals exactly 0.45359237 kilograms, a defined value since 1959. To convert pounds to kilograms, multiply by 0.4536 (or divide by 2.2046). Quick math: 1 lb ≈ 0.45 kg, 10 lbs ≈ 4.5 kg, 100 lbs ≈ 45 kg.
When You'll Need This Conversion
If you live in the US and order something internationally, pricing or shipping may be quoted in kilograms. Doctors, scientists, and most international gyms report weight in kg. Recipes from European cookbooks list ingredients by gram or kilogram, requiring conversion from US pound measurements.
Reference Conversions
1 lb = 0.454 kg. 5 lbs = 2.27 kg. 10 lbs = 4.54 kg. 25 lbs = 11.34 kg. 50 lbs = 22.68 kg. 100 lbs = 45.36 kg. 200 lbs = 90.72 kg. A typical adult weighs 100-220 lbs (45-100 kg).
Avoirdupois vs Troy Pounds
This calculator uses the standard avoirdupois pound (0.45359237 kg), what everyone means by 'pound' in daily life. Troy pounds, used for precious metals and gems, are different: 1 troy lb = 0.3732 kg. Always specify if a quote refers to troy weight.
Common questions
How many kg is 150 lbs?
150 lbs equals 68.04 kg (150 × 0.4536).
What's a quick mental conversion?
Divide pounds by 2.2 for a kg estimate. 150 lbs / 2.2 ≈ 68 kg, accurate to within 0.5%.
How heavy is a stone in kilograms?
1 stone equals 14 pounds = 6.35 kg. Stones are used in the UK and Ireland for body weight but not in the US.
Why is the pound defined in metric units?
Since 1959, the international yard and pound have been redefined as exact metric values. This eliminates discrepancies between US and UK standards and ties imperial units to SI definitions.
Is the kilogram a weight or a mass?
Strictly, kg is a unit of MASS. Pound can refer to mass (pound-mass) or force (pound-force). On Earth, mass and weight are proportional so the distinction rarely matters in daily life.
All conversion runs in your browser. This tool uses the standard avoirdupois pound (0.45359237 kg), the pound everyone means in daily life, not the troy pound used for precious metals.