Weight Unit Converter (kg, lb, oz)

Converts a weight into milligrams, grams, kilograms, tonnes, ounces and pounds. One pound is defined as exactly 0.45359237 kg, and an ounce is a sixteenth of that.

Explanation

Enter a weight and choose its unit, and every other unit follows. Pounds convert to kilograms exactly as easily as kilograms convert to pounds.

The definitions

1 lb = 0.45359237 kg exactly
1 oz = 1/16 lb = 28.349523125 g
1 tonne = 1000 kg

The pound is not "about 0.4536 kg". It is exactly that eight-digit number, fixed by the international agreement of 1959.

Example

Convert 1 pound.

1 \times 0.45359237 = 0.45359237\ \text{kg} = 453.59237\ \text{g}

In ounces it is exactly 16, since a pound is defined as sixteen ounces.

Where it is used

Recipes from abroad: a pound of flour is about 454 g, four ounces of butter about 113 g
Boxing weight classes, and birth weights, which English speakers give in pounds and ounces
Airline baggage limits: 50 lb is about 22.7 kg

Watch out

Mass and weight are different things. Everything here converts mass into mass.

If you want weight as a force, the gravitational pull on a 1 kg mass is 1 kgf = 9.80665 N, and that belongs to the force converter. Take the mass to the Moon and it is still 1 kg, but the force pulling on it drops to a sixth.