Katch-McArdle Calculator
Calculate BMR using the Katch-McArdle equation — typically the most accurate option for athletes and lifters whose body-fat percentage is known.
What is Katch-McArdle?
The Katch-McArdle formula bases metabolic rate on lean body mass instead of total weight. This is more accurate for very lean or very muscular people, where total weight gives a misleading picture. For people without a measured body-fat percentage, predictive equations (Mifflin-St Jeor) remain a better default.
How is it calculated?
BMR = 370 + 21.6 × LBM (kg) where LBM = weight × (1 − body-fat%/100). Multiply by 1.2–1.9 for TDEE.
Frequently Asked Questions
- When is Katch-McArdle most useful?
- For trained populations with measured body-fat percentage.
- How do I get accurate body-fat?
- DEXA, skinfolds, hydrostatic weighing or BIA in that order of accuracy.
- Can I use it for weight loss?
- Yes — it produces a more accurate baseline for very lean clients.