Katch-McArdle BMR Calculator

Calculate your Basal Metabolic Rate using the Katch-McArdle formula, which accounts for your lean body mass.

Katch-McArdle BMR1839 kcal/day

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The Advantage of Katch-McArdle

Most BMR formulas (like Harris-Benedict or Mifflin-St Jeor) estimate your metabolic rate based entirely on your total body weight. The Katch-McArdle equation is unique because it bases its calculation entirely on your Lean Body Mass (LBM).

Why Lean Mass Matters

Muscle tissue is highly metabolically active compared to fat tissue. Two people can both weigh 200 lbs, but if one has 10% body fat and the other has 30% body fat, the leaner person burns significantly more calories at rest. The Katch-McArdle formula accurately accounts for this.

Worked Example

  1. Weight: 80 kg
  2. Body Fat: 15%
  3. Lean Mass = 80 * (1 - 0.15) = 68 kg
  4. BMR = 370 + (21.6 * 68) = 1,839 kcal/day.

Frequently Asked Questions

When should I use this formula over others?

You should use Katch-McArdle if you are exceptionally lean (like a bodybuilder) or exceptionally obese, provided you know your true body fat percentage. If you do not know your body fat percentage, use the Mifflin-St Jeor equation instead.