Fitness & Performance
Katch-McArdle TDEE Calculator
Standard TDEE formulas under-serve muscular bodies. This one runs the whole calculation on lean mass instead.
Katch-McArdle TDEE starts from lean body mass: BMR = 370 + 21.6 × lean kg, then multiplies by an activity factor from 1.2 to 1.9. It's the preferred energy estimate for athletes and muscular builds. Use the result as a training benchmark — retest under the same conditions to track progress.
BMR = 370 + 21.6 × lean kg.
More accurate for trained bodies.
Cut −15–20% · gain +10–15%.
Calculate Your Katch-McArdle TDEE
Your TDEE
What Is Katch-McArdle TDEE?
Lean mass does essentially all of the body's resting metabolic work, so basing TDEE on it removes the main error in standard formulas, muscle being counted as 'excess weight'.
This calculator chains the Katch-McArdle BMR with the standard activity multipliers, giving trained individuals the energy estimate that matches their actual burn.
How It Is Calculated
LBM = weight × (1 − body fat % ÷ 100)
BMR = 370 + 21.6 × LBM
TDEE = BMR × activity factor (1.2–1.9)
Example: Example: 80 kg at 15% fat → 68 kg LBM → BMR 1,839 × 1.55 → TDEE ≈ 2,850 kcal
Katch vs standard estimates (80 kg, 15% fat, active)
| Method | TDEE |
|---|---|
| Katch-McArdle | ≈ 2,850 kcal |
| Mifflin-St Jeor (male, 30, 178 cm) | ≈ 2,720 kcal |
| Difference | +130 kcal, muscle finally counted |
Limitations
- Body-fat input drives accuracy, use a consistent measurement method.
- Same activity-factor caveats apply: people overestimate their level.
- Extremes of body fat reduce formula reliability.
Sources & Review
References used for this calculator’s formulas and thresholds:
Katch-McArdle TDEE FAQ
Why use Katch-McArdle TDEE?
Standard formulas under-estimate muscular people. Lean-mass-based TDEE typically runs 5–10% higher for trained bodies, and matches their real burn.
How is it different from the Katch BMR tool?
This is the full energy picture: Katch BMR multiplied by activity, the number you actually eat against.
What body fat input should I use?
The same one consistently — Navy tape or skinfold both work; the formula tolerates ±3% error well.
A note before you begin: this tool offers educational estimates only. It cannot replace advice from a qualified professional.