Pounds to Kilograms Conversion
Pounds to Kilograms Calculator
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.
Pounds to Kilograms at a Glance
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:
Pounds = Kilograms ÷ 0.45359237
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.
| Pounds | Kilograms (kg) | Grams (g) | Stones & lb | View page |
|---|---|---|---|---|
| 0.25 lb | 0.1134 kg | 113.40 g | 0 st 0.25 lb | View → |
| 0.5 lb | 0.2268 kg | 226.80 g | 0 st 0.50 lb | View → |
| 0.75 lb | 0.3402 kg | 340.19 g | 0 st 0.75 lb | View → |
| 1 lb | 0.4536 kg | 453.59 g | 0 st 1.00 lb | View → |
| 1.5 lb | 0.6804 kg | 680.39 g | 0 st 1.50 lb | View → |
| 2 lb | 0.9072 kg | 907.18 g | 0 st 2.00 lb | View → |
| 2.5 lb | 1.1340 kg | 1,133.98 g | 0 st 2.50 lb | View → |
| 3 lb | 1.3608 kg | 1,360.78 g | 0 st 3.00 lb | View → |
| 4 lb | 1.8144 kg | 1,814.37 g | 0 st 4.00 lb | View → |
| 5 lb | 2.2680 kg | 2,267.96 g | 0 st 5.00 lb | View → |
| 6 lb | 2.7216 kg | 2,721.55 g | 0 st 6.00 lb | View → |
| 7 lb | 3.1751 kg | 3,175.15 g | 0 st 7.00 lb | View → |
| 8 lb | 3.6287 kg | 3,628.74 g | 0 st 8.00 lb | View → |
| 9 lb | 4.0823 kg | 4,082.33 g | 0 st 9.00 lb | View → |
| 10 lb | 4.5359 kg | 4,535.92 g | 0 st 10.00 lb | View → |
| 12 lb | 5.4431 kg | 5,443.11 g | 0 st 12.00 lb | View → |
| 14 lb | 6.3503 kg | 6,350.29 g | 1 st 0.00 lb | View → |
| 15 lb | 6.8039 kg | 6,803.89 g | 1 st 1.00 lb | View → |
| 20 lb | 9.0718 kg | 9,071.85 g | 1 st 6.00 lb | View → |
| 25 lb | 11.3398 kg | 11,339.81 g | 1 st 11.00 lb | View → |
| 30 lb | 13.6078 kg | 13,607.77 g | 2 st 2.00 lb | View → |
| 40 lb | 18.1437 kg | 18,143.69 g | 2 st 12.00 lb | View → |
| 50 lb | 22.6796 kg | 22,679.62 g | 3 st 8.00 lb | View → |
| 60 lb | 27.2155 kg | 27,215.54 g | 4 st 4.00 lb | View → |
| 70 lb | 31.7515 kg | 31,751.47 g | 5 st 0.00 lb | View → |
| 75 lb | 34.0194 kg | 34,019.43 g | 5 st 5.00 lb | View → |
| 80 lb | 36.2874 kg | 36,287.39 g | 5 st 10.00 lb | View → |
| 100 lb | 45.3592 kg | 45,359.24 g | 7 st 2.00 lb | View → |
| 120 lb | 54.4311 kg | 54,431.08 g | 8 st 8.00 lb | View → |
| 140 lb | 63.5029 kg | 63,502.93 g | 10 st 0.00 lb | View → |
| 150 lb | 68.0389 kg | 68,038.86 g | 10 st 10.00 lb | View → |
| 160 lb | 72.5748 kg | 72,574.78 g | 11 st 6.00 lb | View → |
| 175 lb | 79.3787 kg | 79,378.66 g | 12 st 7.00 lb | View → |
| 180 lb | 81.6466 kg | 81,646.63 g | 12 st 12.00 lb | View → |
| 200 lb | 90.7185 kg | 90,718.47 g | 14 st 4.00 lb | View → |
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
| Unit | Pounds Equivalent |
|---|---|
| 1 kilogram (kg) | 2.20462262 lb |
| 1 gram (g) | 0.00220462 lb |
| 1 ounce (oz) | 0.0625 lb (1/16 lb) |
| 1 stone (st) | 14 lb (UK body weight) |
| 1 metric tonne (t) | 2,204.62 lb |
| 1 troy pound (lb t) | 0.822857 lb (avdp) |
| 1 troy ounce (oz t) | 0.0685714 lb (avdp) |
| 1 metric pound (Pfund) | 1.10231 lb (= 500 g) |
| 1 short ton (US) | 2,000 lb |
| 1 long ton (UK) | 2,240 lb |
| 1 grain (gr) | 0.000143 lb (1/7000 lb) |
| 1 hundredweight (cwt US) | 100 lb (short cwt) |
Kilograms Converted to Other Weight Units
| Unit | Kilograms Equivalent |
|---|---|
| 1 pound (lb) | 0.45359237 kg (exact) |
| 1 ounce (oz) | 0.0283495 kg |
| 1 stone (st) | 6.35029 kg (= 14 lb) |
| 1 gram (g) | 0.001 kg |
| 1 milligram (mg) | 0.000001 kg |
| 1 metric tonne (t) | 1,000 kg |
| 1 troy pound (lb t) | 0.3732417 kg (metals) |
| 1 troy ounce (oz t) | 0.0311035 kg (metals) |
| 1 metric pound (Pfund) | 0.5 kg (= 500 g) |
| 1 short ton (US) | 907.185 kg (= 2,000 lb) |
| 1 long ton (UK) | 1,016.05 kg (= 2,240 lb) |
| 1 hundredweight (cwt US) | 45.3592 kg (= 100 lb) |
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
⚖ Body Weight & Medical Dosing
US charts give weight in pounds, but doctors worldwide work in kilograms — and most medication is dosed per kilogram of body weight. A 160 lb patient is 72.6 kg, so a 5 mg/kg dose is 363 mg. Converting first prevents serious dosing errors.
✈ Travel & Immigration Forms
Visa applications, dive certifications, and medical forms outside the US ask for weight in kilograms. Convert your pound figure once — 175 lb is 79.4 kg — and copy the same number onto every form.
🏋 Gym Plates & Lifting
Olympic bars and plates are marked in kilograms, but many US lifters train in pounds. A 225 lb bench is 102.1 kg and a 45 lb plate is 20.4 kg — convert before you compare lifts to international standards.
👶 Newborn & Baby Weight
US hospitals announce birth weight in pounds and ounces, while international records and growth charts use kilograms. A 7 lb 8 oz baby is 3.40 kg — the calculator handles the lb-and-oz split for you.
🚚 International Shipping
US carrier labels show pounds; customs forms and many overseas couriers want kilograms. A 50 lb parcel is 22.7 kg — matching the unit keeps your paperwork, weight limits, and rate brackets consistent.
🍳 Cooking From US Recipes Abroad
American cookbooks list meat and bulk ingredients in pounds. A 3 lb roast is about 1.36 kg — handy when your scale, butcher, or oven chart is calibrated in kilograms.
Frequently Asked Questions
How many kilograms are in 1 pound?
One pound equals exactly 0.45359237 kilograms — roughly 0.45 kg, or about 454 grams. The value is exact because the pound was defined in terms of the kilogram by the 1959 International Yard and Pound Agreement, recognized by NIST and every national metrology institute.
What is the formula to convert pounds to kilograms?
Multiply the pound value by 0.45359237 to get kilograms. To go back, divide kilograms by 0.45359237 (or multiply by 2.2046226218 to return to pounds). For quick mental math, divide pounds by 2.2.
How many kilograms is 150 lb?
150 pounds equals 68.0389 kilograms (68.04 kg rounded), which is about 10 stone 10 lb — close to the average adult body weight. For reference, 140 lb is 63.50 kg, 160 lb is 72.57 kg, and 180 lb is 81.65 kg.
How do I convert pounds to kilograms in my head?
Divide the pounds by 2, then subtract about 10 %. For 100 lb: 100 ÷ 2 = 50, minus 10 % (5) = 45 kg, which is within a fraction of the exact 45.36 kg. Halving alone gives a rough ceiling; trimming the extra 10 % closes most of the gap.
How do I convert my body weight from pounds to kilograms?
Multiply your weight in pounds by 0.45359237, or divide by 2.2046 for the same result. A 130 lb person is 59.0 kg, a 170 lb person is 77.1 kg, and a 200 lb person is 90.7 kg. The kilogram figure is what doctors use for BMI and per-kilogram medication dosing.
Is 1 lb exactly 0.45 kg?
No — that is a rounding. One pound is 0.45359237 kilograms. The “0.45” shortcut is fine for everyday estimates, but it runs slightly light: 100 lb is 45.36 kg, not 45 kg. Use the full factor when accuracy matters, such as medical or shipping figures.
How many kg is 10 lb?
10 pounds equals 4.5359 kilograms (4.54 kg rounded), or 4,535.92 grams. Nearby values: 5 lb is 2.27 kg, 20 lb is 9.07 kg, and 50 lb is 22.68 kg.
Does the material change the pound-to-kilogram answer?
No. Pounds and kilograms both measure mass, so the conversion is constant for every substance. 10 lb of feathers and 10 lb of lead both equal 4.54 kilograms — the lead just takes up less room. Density only matters when converting mass to a volume unit such as liters or cups.
Why isn’t the conversion a round number?
Because the pound and kilogram came from separate historical systems. When they were formally linked in 1959, the pound was fixed at exactly 0.45359237 kilograms — a clean number on the pound side, which makes the inverse (2.2046226218 lb per kg) an uneven decimal. There is no way to make both directions round at once.
How many kilograms is 200 lb?
200 pounds equals 90.7185 kilograms (90.72 kg rounded), or about 14 stone 4 lb. For context, 175 lb is 79.38 kg, 190 lb is 86.18 kg, and 220 lb is 99.79 kg.
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