# kg to lbs

There are 2.204623 pounds (lbs) in 1 kilogram (kg). Both pounds and kilograms are units of mass/weight. Pounds are used in the imperial and US customary systems of measurement, while kilograms are the base unit of mass in the International System of Units (SI).

## kg to lbs conversion

The following converter performs kg to lbs conversion. Just enter a value in either kg or lbs to convert between the two.

 kg lbs

### How to convert kg to lb

To convert kg to lbs, multiply a mass in kilograms by 2.204623 to get a mass in pounds. Similarly, to convert a mass in pounds to kilograms, multiply by 0.45359 (or divide by 2.204623). These conversion factors are based on the relationship between the two measures of mass.

#### How many kilograms are in a pound

There are 2.204623 pounds in a kilogram, or:

1 lb = 0.45359 kg

#### How many pounds are in a kilogram

There are 0.45359 kilograms in a pound, or:

1 kg = 2.204623 lbs

Below is a kilograms to grams (and vice versa) conversion example.

Examples

1. Convert 55 kilograms to pounds:

55 kg × 2.204623 = 121.25 lbs

2. Convert 170 pounds to kilograms:

170 lbs ÷ 2.204623 = 77.111 kg

## What is a kilogram

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

### Kilogram definition

The kilogram was redefined in 2019 to be based on three physical constants speed of light, the atomic transition frequency of cesium, and the Planck constant. The actual value of the mass remains mostly consistent with the previous definition, which was based on an actual physical object made of a platinum alloy. The redefinition of the kilogram is intended to improve its definition, since the physical platinum alloy degrades over time. The redefinition bases it on physical constants that never change.

### History of the kilogram

The definition of the kilogram has changed a number of times throughout the course of history. In 1793, it was defined as the mass of 1 litre of water. In 1795 it was defined as the mass of one cubic centimetre of water at the melting point of ice. It was redefined a few more times, and in 1875, one of the longest-lasting definitions of the kilogram was produced: a platinum alloy object about the size of a golf ball named the International Prototype of the Kilogram. The prototype was created in 1875 and adopted in 1889, and this definition of the kilogram lasted until 2019, when it was redefined in terms of the Planck constant, the speed of light, and the atomic transition frequency of cesium.

The kilogram is the only SI base unit that has an SI prefix (kilo-). The reason the base unit is the kilogram rather than the gram is because when this physical standard of mass was created in 1799, there were no methods for measuring masses that were as small as a gram.

### Uses of kilograms

The kilogram is widely used throughout the world in everyday as well as scientific contexts. Most countries around the world have adopted SI with one notable exception being the United States, which still largely uses the US customary system in everyday life. While the US also uses SI in many other contexts, it has still not officially adopted SI.

## What is a pound

A pound is a unit of mass in the US customary system of units.

### Pound definition

The definition of the pound (lb) is based on the international avoirdupois pound, which is defined as exactly 0.45359237 kilograms. It is equivalent to 16 avoirdupois ounces.

### History of the pound

The definition of the pound has changed throughout the course of history. It originated from the Roman libra, and went through a number of different definitions until the development of the international avoirdupois pound in the 13th century. This definition was updated in 1959, and this pound was based on a prototype weight that could be divided into 16 ounces.

### Uses of pounds

Pounds are the primary unit of weight used in the United States for everyday purposes. They are not used much anymore in the United Kingdom (UK), since the UK started the process of metrication back in 1965. Both countries use the kilogram as well in many contexts such as science, the military, industry, and more. This is to provide consistency when communicating with other countries, since most other countries use the kilogram as their measurement of mass/weight, rather than the pound or other units of weight.

## Kilograms to pounds conversion table

kilogram (kg) pound (lb)
0.01 0.0220462262
0.1 0.2204622622
1 2.2046226218
2 4.4092452437
3 6.6138678655
5 11.0231131092
10 22.0462262185
20 44.092452437
50 110.2311310924
100 220.4622621849
1000 2204.6226218488