What this calculator does
RMR from lean mass (Katch-McArdle) works out resting metabolic rate estimated from lean body mass rather than total weight. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaRMR = 370 + 21.6 × lean body mass(kg); LBM = weight × (1 − body fat% / 100)
The inputs explained
| Field | What to enter |
|---|---|
| Weight (kg) | A number, measured in kg. Starts at 75. |
| Body fat (%) | A number, measured in %. Starts at 20. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with weight
Every other input is held at the calculator’s starting values while weight varies. Select any row to load that scenario into the calculator.