Pounds to Kilograms Converter: Simple and Handy

0 kg

The formula

1 pound equals exactly 0.45359237 kilograms — this is the internationally defined avoirdupois pound, fixed since 1959, not a rounded estimate. The calculator multiplies your input by that exact factor as you type.

Worked example

A 150 lb adult converts to 150 × 0.45359237 = 68.0388... kg, displayed as 68.04 kg. A 5 lb bag of sugar converts to 5 × 0.45359237 = 2.27 kg.

Reference weights

1 lb = 0.45 kg. 10 lb ≈ 4.54 kg. 44 lb ≈ 20.00 kg (close to a round 20 kg checked-baggage allowance). 220 lb ≈ 99.79 kg.

Why this is exact, not approximate

Unlike some unit pairs that rely on measured physical constants, the pound-to-kilogram relationship was formally defined by international agreement (the 1959 International Yard and Pound Agreement) as exactly 0.45359237 kg. There's no rounding error hiding in the source factor — only in the final displayed decimal places.