Pounds to Kilograms

How to use Pounds to KG Converter

1. 1
   Enter the pounds. Decimals are fine — enter 8.5 rather than 8 lb 8 oz.
2. 2
   Read the kilograms. To three decimals, with grams underneath for small weights.

About converting pounds to kilograms

Pounds to kilograms is one of the few conversions where getting it wrong has consequences beyond inconvenience. Medicine dosing is specified per kilogram, so a weight entered in pounds and treated as kilograms overdoses by a factor of 2.2 — an error frequent enough that hospital systems increasingly refuse to accept pounds at all. Aviation has its own version of this. In 1983 an Air Canada 767 ran out of fuel mid-flight because a fuelling calculation used pounds where the aircraft, unusually for the fleet at the time, was calibrated in kilograms; the aircraft glided to a landing and the incident is still taught as a case study in unit discipline. The everyday cases are less dramatic and more common: freight priced per kilogram and quoted in pounds, luggage allowances published in one unit and scales calibrated in the other, recipes crossing between American volume-and-pound conventions and European weight-based ones. The mental shortcut worth knowing is halve and subtract a tenth, which lands within one percent. For anything where the number matters, convert properly and label the unit explicitly — most of these failures come from a number written without one.

Frequently asked questions