Lunia · Free tools
BMR Calculator
Compare three common resting-energy equations.
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How this calculator works
Mifflin-St Jeor uses 10W + 6.25H − 5A plus the selected sex coefficient. Revised Harris-Benedict uses its sex-specific height, mass and age coefficients. Katch-McArdle uses 370 + 21.6 × lean body mass in kg.
A worked example
Body weight: 70 · Weight unit: Kilograms · Height: 170 · Length unit: Centimetres · Age in years: 30 · Sex coefficient used by the formula: Female coefficient · Estimated body fat for Katch-McArdle (%): 25
- Mifflin-St Jeor
- 1,452 kcal/day
- Revised Harris-Benedict
- 1,492 kcal/day
- Katch-McArdle
- 1,504 kcal/day
These are illustrative inputs, not personal recommendations.
Common questions
Why are the three estimates different?
They were developed from different samples and inputs. Agreement does not prove accuracy, and disagreement highlights the uncertainty of formula-based estimates.
How should I use the result?
Adult estimates only. These models are not individual nutrition plans and are not intended for pregnancy, breastfeeding, children or medical conditions affecting energy needs. Resting energy is not a recommended daily intake. A body-fat estimate adds uncertainty to the Katch-McArdle result.
Sources & method references
Formula-based results are estimates, not individual medical advice.