KG to LBS Converter
Convert kilograms to pounds and pounds back to kilograms, with stones for good measure.
Formula and sources updated · Data sources · 1View algorithm, constants and default inputs (JSON)
1 lb = 0.45359237 kg
About this calculator
A pound is defined as exactly 0.45359237 kilograms. Body weight is the most common use, but the same conversion applies to any mass.
Worked example
calculated with the default values below
Value 70 · Direction ⇄ · Decimal places 4 · From Kilograms (kg) · To Pounds (lb) Result 154.3236 · In stones 11.023 st · In grams 70,000 g
Method and assumptions
Formula basis and scope
1 avoirdupois pound = 0.45359237 kg.
Only the displayed unit definitions are converted; rounding and measurement uncertainty are separate.
Data sources
Disclaimer
These calculators give general conversion results. Rounding and the precision of the value you enter both affect the output, so treat displayed decimals as indicative rather than exact.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
lb = kg ÷ 0.45359237; kg = lb × 0.45359237; st = kg ÷ 6.35029318
- kg
- Kilograms
- lb
- Pounds
- st
- Stones
- g
- Grams
Exact international conversion factors; grams = kg × 1000.
Frequently asked questions
Is the pound an exact value?
Yes. Since 1959 the international avoirdupois pound has been defined as exactly 0.45359237 kilograms, so the conversion factor has no uncertainty at all. Any discrepancy comes from rounding in the display or from the accuracy of the scale — never from the definition itself.
Why does my gym plate not match the conversion?
Because plates are nominal rather than calibrated. A twenty kilogram plate is permitted to sit slightly either side of its marked weight, and older or worn plates drift further. Competition discs are held to a much tighter tolerance than those sold for home use, which is why a bar loaded with a claimed total can weigh noticeably more or less.