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Free Katch-McArdle Calculator

Calculate your BMR using the Katch-McArdle formula, which uses lean body mass for more accurate results — ideal for athletes and lean individuals.

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About the Katch-McArdle Formula

The Katch-McArdle formula calculates BMR based on lean body mass rather than total body weight. This makes it more accurate for individuals who know their body fat percentage, especially athletes and people with above-average muscle mass.

BMR = 370 + (21.6 × lean body mass in kg)

Where lean body mass = weight × (1 − body fat % / 100)

Unlike the Mifflin-St Jeor and Harris-Benedict formulas, Katch-McArdle does not use gender, age, or height as variables. It relies solely on lean body mass, which is why it requires a body fat percentage measurement.