Kilograms to pounds

One kilogram equals 2.20462 pounds. To convert, multiply the kilogram figure by 2.20462; to go the other way, divide by the same number. The kilogram is the SI base unit of mass and the pound is defined as exactly 0.45359237 kg, so the relationship is fixed rather than approximate.

The two-and-a-bit relationship is easy to do in your head if you accept a small error: double the kilograms and add ten per cent. Eighty kilograms doubles to 160, plus sixteen, gives 176 — the exact answer is 176.37. That shortcut is fine for luggage and useless for anything a doctor or a shipper will act on, which is what the full precision above is for.