Convert weight and mass units — kilograms, pounds, ounces, grams, tons, stones.
| Unit | Name | Value |
|---|---|---|
| kg | Kilogram | 0.453592 |
| g | Gram | 453.592 |
| mg | Milligram | 453592 |
| t | Metric Ton | 0.000453592 |
| oz | Ounce | 16 |
| st | Stone | 0.071428549 |
The Pound (lb) and the Kilogram (kg) are both units of weight & mass. Converting between them is straightforward using the formula above.
Formula: 1 lb = 0.453592 kg
This converter uses internationally recognized conversion factors. All calculations are performed client-side in your browser — no data is sent to any server.
| Pound (lb) | Kilogram (kg) | Real-world context |
|---|---|---|
| 1 lb | 0.453592 kg | loaf of bread |
| 10 lb | 4.53592 kg | small dog |
| 100 lb | 45.3592 kg | child |
| 500 lb | 226.796 kg | |
| 1000 lb | 453.592 kg |
1 pound (lb) equals exactly 0.453592 kilograms (kg). Use the formula: lb × 0.453592 = kg.
To convert pounds to kilograms, multiply your value in pounds by 0.453592. For example, 5 lb × 0.453592 = 2.26796 kg.
100 pounds = 45.3592 kilograms. Calculation: 100 × 0.453592 = 45.3592.
To convert kilograms back to pounds, divide by 0.453592 (or multiply by 2.2046244). Example: 10 kg ÷ 0.453592 = 22.0462442 lb.
Yes. This converter uses the internationally recognised exact conversion factor: 1 lb = 0.453592 kg. All calculations are performed in your browser with no rounding until display.
10 pounds = 4.53592 kilograms. Simply multiply by 0.453592.
Converting pounds to kilograms is commonly needed for everyday tasks like cooking recipes, body weight tracking, shopping internationally, or shipping parcels where one system uses lb and another uses kg.
The pound (lb) is the primary unit of mass in the US customary and British imperial systems, equal to exactly 453.59237 grams since the International Yard and Pound Agreement of 1959. It is subdivided into 16 ounces. The abbreviation "lb" comes from the Latin libra (scales/balance), while "pound" derives from Latin pondus (weight).
The kilogram (kg) is the SI base unit of mass — one of seven fundamental units in the International System. Equal to exactly 1,000 grams, it is the foundation of weight measurement in science, medicine, engineering, and commerce worldwide. Uniquely among SI base units, the kilogram is named with a metric prefix ("kilo-" = 1,000).
The pound traces its origins to ancient Rome's libra pondo (pound weight, ~329 g). Various standards existed in medieval Europe — Troy, Tower, and merchant pounds — until the avoirdupois pound emerged in 13th–14th century England for general trade. The British Weights and Measures Act 1878 formalised it. The modern definition (453.59237 g) was fixed by the US, UK, Australia, Canada, New Zealand, and South Africa in 1959.
Interesting fact: The word "pound sterling" originally meant one pound (12 troy ounces) of sterling silver. Today's British pound currency takes its name from the unit of mass, not the other way around.
Defined in 1795 by the French Revolutionary government as the mass of one cubic decimetre of distilled water at 4 °C. A platinum prototype (the Kilogramme des Archives) was created in 1799. From 1889 until 2019, the world's mass standard was the International Prototype Kilogram — a platinum-iridium cylinder stored in Sèvres, France. In 2019, the kilogram was redefined in terms of Planck's constant (h = 6.626 070 15 × 10⁻³⁴ J·s), eliminating the need for a physical artifact.
Interesting fact: The IPK and its official copies drifted apart by up to 50 micrograms over 130 years, motivating the 2019 redefinition. The kilogram is the only SI unit whose name starts with a prefix.