Convert kilograms to pounds

The formula

pounds = kilograms × 2.2046226

kilograms to pounds — quick reference

Double it, then add a tenth

Doubling and adding ten per cent gives 2.2 times, and the true factor is 2.2046 - an error of one part in five hundred. Eighty kilograms becomes 160 plus 16, or 176 lb, against a true 176.37. There is no easier arithmetic anywhere in imperial conversion, and it is accurate enough to quote out loud.

The landmarks worth holding are the ones that recur. 23 kg, the standard checked baggage allowance, is 50.7 lb, which is why airlines print 50 lb and 23 kg side by side as though they were the same number. And a 20 kg Olympic barbell is 44.1 lb, not the 45 lb bar of an American gym; they are different bars.

The pound is defined from the kilogram, and there is more than one pound

Since 1959 the international avoirdupois pound has been exactly 0.45359237 kg by definition, so this conversion is legally exact rather than measured. Every English-speaking country signed the agreement, which ended a long period in which the American and imperial pounds differed very slightly from each other.

The avoirdupois pound is not the only one. Precious metals use the troy scale, where an ounce is 31.10 g and twelve make a troy pound of 373.24 g - so a pound of gold weighs less than a pound of sugar, and a bullion weight in kilograms converted with the everyday factor overstates the ounces by about ten per cent.

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