Calculator
Lbs to Kg Calculator
Quick answer
Type pounds or kilograms. The other field updates with 1 pound = 0.45359237 kilograms, the international avoirdupois pound.
Plates do not convert into neat numbers. 45 lb is 20.4117 kg, not 20 kg. A 20 kg plate is 44.092 lb, not 45. Load the bar in one system.
Need a 1RM first? Use the one rep max calculator →
Estimates only. Testing a true max carries risk; use a spotter or safety arms. Not medical advice.
Factor: 1 lb = 0.45359237 kg. 225 lb = 102.06 kg.
On this page
How does the lbs to kg calculator work?
Kilograms = pounds × 0.45359237. Pounds = kilograms / 0.45359237. The same factor is used everywhere else on OneRepMax before a DOTS or Wilks polynomial runs.
Display rounding on the lifting calculators is separate. This page keeps more of the fraction so you can see the conversion itself.
What inputs does it need?
One weight. Either field works. Clearing a field stops the update until a positive number is back.
Body weight and bar weight use the same factor. There is no 'gym kilogram'.
Worked example with sample numbers
Example only: 225 lb × 0.45359237 = 102.058 kg. People often call that 100 kg and are about 2 kg off.
100 kg / 0.45359237 = 220.462 lb. A bar loaded to 100 kg is not a 225 lb bar.
Common mistakes
Using 2.2 as the factor. 1 / 2.2 = 0.454545…, which is a bit high. Close enough for a grocery bag, sloppy for a total you want to score.
Converting each plate and then also converting the bar with a different factor. Convert the final load once.
FAQ
What is the exact pounds to kilograms factor?
1 pound = 0.45359237 kilograms.
Is a kilo plate 2.2 pounds?
A kilogram is about 2.20462 pounds. 2.2 is the shorthand.
Why do powerlifting scores need kilograms?
DOTS, Wilks, and IPF GL are defined on kilograms. This site converts first, then scores.
Should I round to the nearest plate?
After you decide which plates you are actually loading. The conversion and the plate math are different steps.
Is stone supported?
No. Pounds and kilograms only.