Pounds to Kilograms Converter
Enter a value below to convert pounds to kilograms - one pound is exactly 0.45359237 kg (1 kg is about 2.2046 lb). For the reverse, use our kilograms to pounds converter.
1 lb = 0.453592 kg. Enter a value above to convert pounds to kilograms. Need the reverse? See kg to lbs.
Pound
- Definition
- A pound (symbol: lb) is a unit of mass in the imperial and US customary systems, defined since 1959 as exactly 0.45359237 kilograms. One pound is divided into 16 ounces.
- History / origin
- The word "pound" comes from the Latin "libra pondo" ("a pound by weight"), which is why the symbol is "lb". Many regional pounds existed historically before the international avoirdupois pound was standardized at exactly 0.45359237 kg in 1959.
- Current use
- The pound is used mainly in the United States for body weight, food packaging and everyday measurements, and remains in common use in the United Kingdom alongside the kilogram (for example, body weight in stones and pounds).
Kilogram
- Definition
- A kilogram (symbol: kg) is the base unit of mass in the International System of Units (SI). Since 2019 it has been defined by fixing the numerical value of the Planck constant; for everyday purposes it is very close to the mass of one liter of water.
- History / origin
- The kilogram was introduced with the metric system in 1795. From 1889 to 2019 it was defined by a platinum-iridium cylinder, the International Prototype Kilogram, kept near Paris - the last SI unit tied to a physical artifact before the 2019 redefinition through constants of nature.
- Current use
- The kilogram is used worldwide for almost all mass measurements - groceries, body weight outside the United States, science and industry - in every country that has adopted the metric system.
Pound to kilogram conversion table
| Pound [lb] | Kilogram [kg] |
|---|---|
| 0.1 lb | 0.045359237 kg |
| 0.5 lb | 0.226796185 kg |
| 1 lb | 0.45359237 kg |
| 2 lb | 0.90718474 kg |
| 5 lb | 2.26796185 kg |
| 10 lb | 4.5359237 kg |
| 25 lb | 11.33980925 kg |
| 50 lb | 22.6796185 kg |
| 100 lb | 45.359237 kg |
| 500 lb | 226.796185 kg |
| 1,000 lb | 453.59237 kg |
Popular pound to kilogram conversions
Everyday body weights and common loads in kilograms, rounded to two decimals - the pound values people look up most.
| Pound [lb] | Kilogram [kg] |
|---|---|
| 1 lb | 0.45 kg |
| 5 lb | 2.27 kg |
| 10 lb | 4.54 kg |
| 20 lb | 9.07 kg |
| 50 lb | 22.68 kg |
| 100 lb | 45.36 kg |
| 120 lb | 54.43 kg |
| 140 lb | 63.50 kg |
| 150 lb | 68.04 kg |
| 160 lb | 72.57 kg |
| 180 lb | 81.65 kg |
| 200 lb | 90.72 kg |
How to convert pounds to kilograms
To convert pounds to kilograms, multiply the number of pounds by 0.45359237. For example, 150 lb × 0.45359237 = 68.04 kg (or divide by 2.2046).
One pound is defined as exactly 0.45359237 kilograms, so converting pounds to kilograms is a single multiplication - no rounding is needed in the definition itself:
kilograms = pounds × 0.45359237
1 lb = 0.45359237 kg · 1 kg = 2.2046226218 lb
Example. To convert 180 pounds to kilograms, multiply by 0.45359237: 180 lb = 180 × 0.45359237 = 81.65 kg. Going the other way, 70 kg is 70 × 2.2046226218 = 154.32 lb.
When you need to convert pounds to kilograms
Pound-to-kilogram conversion is what you reach for when a US customary weight has to fit a metric system. Common cases:
- Recording a body weight given in pounds onto a metric medical chart or fitness app.
- Setting weightlifting loads in kilograms from a program written in pounds.
- Declaring parcel and freight weights in kilograms for international shipping.
- Converting US food and recipe weights to the grams and kilograms used elsewhere.
- Entering equipment or luggage weights into systems that expect kilograms.
Frequently asked questions
How many kg is 1 pound?
One pound equals 0.4536 kilograms (0.45359237 kg exactly) - just under half a kilogram.
How do I convert lbs to kg?
Multiply the number of pounds by 0.45359237, or divide by 2.2046. For example, 150 lb = 150 × 0.45359237 = 68.04 kg.
Is 1 pound exactly 0.45359237 kg?
Yes - exactly, by definition. The 1959 international agreement fixed the avoirdupois pound at 0.45359237 kg, so it is not a rounded approximation.
How many kg is 150 pounds?
150 pounds equals 68.04 kg (68.0388555 kg to be exact).
How many kg is 200 pounds?
200 pounds equals 90.72 kg (90.718474 kg to be exact).
Is a pound lighter than a kilogram?
Yes. One pound is about 0.45 kg, which is less than half a kilogram; it takes about 2.2 pounds to make one kilogram.
How do I convert lbs to kg in my head?
Halve the pounds and take off about 10 percent. For example, 150 lb is roughly 75 - 7.5 = 67.5 kg, and the exact value is 68.04 kg.
How many pounds is 70 kg?
70 kg equals 154.32 pounds. To convert kilograms to pounds, multiply by 2.2046226218.
Popular weight unit conversions
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Convert pounds to other weight units
Convert a pound measurement into any other weight unit our converter supports.