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Pounds to Kilograms (lb to kg)
Convert pounds to kilograms instantly. The formula is kg = pounds ÷ 2.20462 — divide pounds by 2.20462 — luggage limits, gym plates and medical doses all use it. Everything is computed locally in your browser; nothing is uploaded.
How to convert lb to kg
The exact conversion factor between pounds and kilograms gives the formula kg = pounds ÷ 2.20462. Divide pounds by 2.20462 — luggage limits, gym plates and medical doses all use it.
For a rough mental estimate, remember that 1 lb = 0.4536 kg. To go the other way, see the kilograms to pounds converter — it uses the reciprocal factor.
Worked examples
Example: convert 10 lb to kg. Apply the formula — kg = pounds ÷ 2.20462 — and you get 4.54 kg. Reverse-check it by using the kilograms to pounds to come back to 10 lb; if you do not land on the original number, a factor was inverted.
Example: convert 200 lb to kg. Apply the formula — kg = pounds ÷ 2.20462 — and you get 90.72 kg. Reverse-check it by using the kilograms to pounds to come back to 200 lb; if you do not land on the original number, a factor was inverted.
Where the factor comes from
The pound used today is the international avoirdupois pound, defined since 1959 as exactly 0.45359237 kilograms. The kilogram itself was redefined in 2019 in terms of the Planck constant, so the chain of custody now runs from a universal physical constant down to your kitchen scale. Because both ends of the chain are exact, converting is pure arithmetic — the only rounding happens when a result is displayed.Common mistakes
Confusing mass and force. Pounds-force (lbf) and pounds-mass (lb) are different physical quantities. Recipes and body weight use mass — the factor on this page applies.
Avoirdupois vs troy. Gold, silver and gemstones use the troy ounce (31.103 g), which is about 10% heavier than the avoirdupois ounce (28.35 g) on this page.
Double rounding. kg → lb → oz in sequence compounds rounding error. Convert directly to the final unit in one step.
Quick mental shortcuts
Mental shortcuts: kg → lb ≈ ×2.2 (75 kg ≈ 165 lb); lb → kg ≈ ÷2.2; g → oz ≈ ÷30 (a 100 g chocolate bar is about 3.5 oz). For cooking, weigh once and remember: 1 stick of butter = 113 g = 8 tbsp.
Common lb to kg conversions
| Pound (lb) | Kilogram (kg) |
|---|---|
| 1 | 0.4536 |
| 10 | 4.54 |
| 50 | 22.68 |
| 100 | 45.36 |
| 150 | 68.04 |
| 200 | 90.72 |
FAQ
How do I convert lb to kg?
kg = pounds ÷ 2.20462. Divide pounds by 2.20462 — luggage limits, gym plates and medical doses all use it.
What is 10 lb in kg?
10 lb equals 4.54 kg. Use the converter above for any value.
How do I convert kg back to lb?
Use the reverse conversion — see our kilograms to pounds converter. The calculator above also shows the reciprocal rate.
Is the lb-to-kg conversion exact?
Yes — modern units are defined by international agreement with exact factors (e.g. 1 inch = 2.54 cm exactly). Results are rounded only for display.
More conversions
cm → inin → cmmm → inin → mmm → ftft → mkm → mimi → kmkg → lbg → ozoz → g°C → °F°F → °Cgal → LL → galg → cupcup → gg → tbsptbsp → gg → mlml → gml → cupcup → mlfl oz → mlml → fl oz
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