Katch-McArdle BMR calculator
Because it works from lean mass, the equation needs no age or sex and suits people with a lot of muscle.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter weight and body fat.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Lean mass = weight × (1 − body fat % ÷ 100). BMR = 370 + 21.6 × lean mass (kg).
Example
Inputs: Weight = 70 kg, Body fat = 20 %. Result: BMR: 1,580 kcal/day; Lean body mass: 56 kg; Fat mass: 14 kg.
Limits and caveats
- It is only as good as the body fat figure you enter; home scales can be several points off.
- A statistical estimate for adults, not a lab measurement.
Questions about this tool
How can I find my body fat percentage?
Use a body composition scale or the US Navy tape method with neck and waist, which has its own calculator here.
When should I use Katch-McArdle instead of Mifflin?
When you know your body fat reasonably well, especially if you carry more muscle than average.
Why does it not ask for age or sex?
Their effect shows up mainly through lean mass, which is what the equation uses.