Pounds to Kilograms Conversion

Have a weight in pounds and need it in kilograms? The calculator above converts any value the moment you type it, and the reference table further down lists every commonly searched pound amount — from a quarter pound up to two hundred. The relationship is fixed and exact: 1 pound = 0.45359237 kilograms, set by the 1959 International Yard and Pound Agreement. Whether you are giving your body weight to an overseas doctor, filling in a metric immigration form, loading kilogram-marked gym plates, or matching a US shipping label to a kilogram-based customs declaration, the same multiplier always applies.

How to Convert Pounds to Kilograms

Converting pounds into kilograms is a single multiplication. Both are units of mass, so no density, ingredient, or temperature value ever enters the calculation. The internationally agreed factor is:

Worked example: 150 × 0.45359237 = 68.04 kilograms — roughly the body weight of an average adult. Going the other way, 68.04 ÷ 0.45359237 = 150 lb. For mental math, divide the pound figure by 2.2; you will land within about 0.2 % of the exact answer, which is close enough for body weight, luggage, or groceries. Prefer multiplying? Times the pounds by 0.4536, or simply read the result straight off the calculator above.

Converting Body Weight From Pounds to Kilograms

This is the most common reason people convert pounds to kilograms. US scales, charts, and ID documents quote weight in pounds, but doctors, gyms, and forms outside the US expect kilograms — and crucially, medication is dosed per kilogram of body weight. A 150 lb adult is 68.0 kg, a 180 lb adult is 81.6 kg, and a 200 lb adult is 90.7 kg. Convert once and the same kilogram figure works for BMI, anesthesia, and per-kilo drug dosing.

Converting Pounds-and-Ounces Values

US scales and birth records often show weight as “X lb Y oz” — a 7 lb 8 oz newborn, say. To convert that to kilograms, first turn the ounces into a fraction of a pound (divide by 16), add it to the whole pounds, then multiply by 0.45359237. For 7 lb 8 oz: 8 ÷ 16 = 0.5, so 7.5 × 0.45359237 = 3.40 kg. The calculator above also accepts decimal pounds directly, so you can enter 7.5 lb and get the same answer.

Which Pound Are You Starting From?

The calculator assumes the standard avoirdupois pound — the everyday pound used for body weight, food, luggage, and freight across the US, UK, and Commonwealth. Two other pounds still circulate and give different kilogram values, so it is worth knowing which one you actually hold:

• Avoirdupois pound (lb): 1 lb = 0.45359237 kg exactly. The default everywhere for general weight, with 16 ounces to the pound. This is what the calculator above uses.
• Troy pound (lb t): used only for precious metals. 1 troy pound = 0.3732417 kg, because it contains just 12 troy ounces (373.24 g) rather than 16 avoirdupois ounces. A troy pound of gold is lighter than an everyday pound of sugar.
• Metric pound (Pfund): an informal European unit equal to exactly 500 g, so 1 Pfund = 0.5 kg. Common at German, Austrian, and Swiss markets. If a European source says “Pfund,” it means half a kilo, not 0.4536 kg.

Pounds to Kilograms Quick Reference Chart

Complete Pounds to Kilograms Conversion Table

This table lists the most-requested pound values with their kilogram equivalents, the gram value for fine-scale work, and the stones-and-pounds breakdown used for UK body weight. For anything not shown, type the number into the calculator at the top, or follow a row’s “View” link for a dedicated breakdown page.

Units of Measurement

The pound and the kilogram are both mass units — they measure how much matter an object contains, not how much space it fills. That is precisely why the conversion never depends on the material. Five pounds of feathers and five pounds of steel both equal 2.27 kilograms; the steel simply takes up far less room. Mass-to-mass conversions are always a single fixed multiplication — you only need a density figure when one side is a volume unit such as cups, liters, or teaspoons.

What is a Pound?

The pound is the principal mass unit of the US customary and imperial systems. It descends from the Roman libra pondo — “a pound by weight” — which is why it is abbreviated “lb” and why British currency uses the £ sign. Medieval Europe juggled dozens of competing pounds; the modern avoirdupois pound was standardized through the English wool trade and finally locked to the metric system in 1959, when it was defined as exactly 0.45359237 kilograms. Sixteen ounces make a pound, and fourteen pounds make a stone.

What is a Kilogram?

The kilogram is the base unit of mass in the International System of Units (SI) and the foundation of the entire metric weight system — a gram is a thousandth of a kilogram and a tonne is a thousand kilograms. Since the 2019 SI redefinition, the kilogram has been defined through Planck’s constant rather than a physical metal cylinder, making it a fully reproducible standard. Its symbol is “kg.” Outside the United States, the kilogram is the default unit for body weight, produce, luggage, and almost everything sold by weight, which is exactly why converting from pounds is so often necessary.

Pounds Converted to Other Weight Units

Kilograms Converted to Other Weight Units

Real-World Reference: Pounds You Meet Every Day

Pounds turn up on US bathroom scales, grocery labels, dumbbells, and luggage tags. Use the references below to picture a pound value when you have no scale handy, or to sanity-check the kilogram equivalent before you trust it.

When You’ll Need to Convert Pounds to Kilograms

Frequently Asked Questions

Popular Pounds to Kilograms Conversions

These are the pound values our visitors look up most often. Each card links to a dedicated calculator page with the precise kilogram amount, the gram and stone equivalents, a full multi-unit table, and a printable chart.

More Frequently Searched Pound Amounts

Related Weight Conversions

• Kilograms to Pounds — the reverse direction