Convert pounds to kilograms

Explanation

From this page you can convert pounds to kilograms (or lbs to kg) simply, by using the application above.

In case you are wondering, to convert from pounds to kilograms you need to multiply by 0.4536. This factor is calculated using the respective definitions of the two units you can find below.

Formula

1 lb≈0.4536 kg

poundslb

dimension	mass
symbol	lb
synonyms	lbs

The pound (lb) is the base unit of mass in the international mass and length units.

Definition of the pound

One pound is defined as being exactly equal to 0.45359237 kilograms.

From the Weights and Measures Act of 1985: PART VI: Measurement of Mass

History

From the Roman libra pondo, meaning a pound of weight. The word libra gave the abbreviation lb and pondo, the name of the unit.

Equivalences

One pound is equivalent to:

Some Facts

The gorilla is the biggest ape with a weight between 350 and 450 pounds on average. The heaviest silverback ever recorded weighed 589 pounds. He was shot in Ambam, Cameroon presumably by bad people.

International Mass Units

grain	gr
dram	dr	27¹¹⁄₃₂ grains
ounce	oz	16 drams
pound	lb	16 ounces
stone*	st	14 pounds
quarter*	qr	2 stones
short hundredweight^†	cwt	100 pounds
long hundredweight*	cwt	4 quarters
short ton^†	st	20 short hundredweight
long ton*	lt	20 long hundredweight

* specific to the United Kingdom

^† specific to the United States of America

The International Mass and Length Units

The International Mass and Length Units are units based on the international yard and the international pound.

They were created in 1959 when Australia, Canada, New Zealand, South Africa, the United Kingdom and the United States of America agreed upon a common definition of the yard and the pound.

Related Conversions

kilogramskg

dimension	mass
system	International system of units (SI)
symbol	kg
synonyms	kilos

The kilogram (kg) is the base unit of mass in the International System of Units.

Definition of the kilogram

It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 x 10^–34 when expressed in the unit J s, which is equal to kg m² s^–1, where the metre and the second are defined in terms of c and ∆ν_Cs.

Definition from the BIPM: Unit of mass

History

The first definition of the kilogram was "the mass of a liter of water". But this proved impractical and in 1889, the International Prototype Kilogram, a cylinder of platinum-iridium alloy, was made to serve as the reference.

In 1949 the mass of the IPK was found to be deverging from its copies. So, in order to ensure the stability of the unit, a new definition was devised based on the Planck constant and on 20 May 2019 this new definition came into effect.

Equivalences

One kilogram is equivalent to:

Some Facts

With an average of 1.4 kg (3 lbs), ostrich eggs are huge, yet, they are the smallest eggs relative to the size of the adult bird.

Prefix

kilo

10³

The prefix kilo- comes from the ancient Greek chilioi meaning thousand. The associated multiplicative factor is 1000 or 10³.

SI Mass Units

nanogram	ng	0.000000001
microgram	µg	0.000001
milligram	mg	0.001
gram	g	1
kilogram	kg	1000
megagram	Mg	1000000

The International System of Units

The International System of Units or SI (from the French Système international (d'unité)), also called metric system in the U.S., is a coherent system of units that was published 1960. It is official in nearly every country.

The General Conference on Weights and Measures (Conférence générale des poids et mesures) is tasked with overseeing the SI.