Clinical Medicine & Physiology
Katch-McArdle BMR (370 + 21.6 * LBM) & Boer (1984) Lean Body Mass Calculator
Calculate sex-neutral Basal Metabolic Rate RDEE = 370 + 21.6 * LBM_kg via Frank I. Katch and William D. McArdle’s equation, paired with P. Boer’s (1984) isotope-validated Lean Body Mass formulas when DXA/skinfolds are unavailable.
Why Katch-McArdle needs NO sex term once Fat-Free Lean Body Mass is isolated!
Most resting calorie differences between men and women of equal scale weight disappear once metabolically sluggish adipose tissue is subtracted! Formulated by exercise physiologists Frank I. Katch and William D. McArdle (Exercise Physiology: Energy, Nutrition, and Human Performance), the Katch-McArdle Basal Metabolic Rate Equation predicts resting daily energy expenditure across BOTH sexes from a single variable — Lean Body Mass LBM = Weight_kg * (1 - %BF / 100): BMR_KM (kcal/day) = 370 + 21.6 * LBM_kg (giving ~130 kcal/day slightly more conservative baseline than Cunningham’s 500 + 22 * LBM endurance-athlete curve)!
When direct body-fat % isn’t measured, P. Boer’s (1984, American Journal of Physiology; widely preferred in CT contrast and obese anesthesiology dosing) Lean Body Mass equations estimate LBM cleanly from Weight (kg) and Height (cm): LBM_Boer_Men = 0.407 * Weight_kg + 0.267 * Height_cm - 19.2, and LBM_Boer_Women = 0.252 * Weight_kg + 0.473 * Height_cm - 48.3!
| Subject Profile | Boer (1984) Lean Body Mass (kg) | Katch-McArdle BMR = 370 + 21.6 * LBM | Moderate Activity TDEE (x 1.55) |
|---|---|---|---|
| Adult Male (180 cm, 82 kg) | 62.23 kg LBM | 1,714 kcal/day | 2,657 kcal/day |
| Adult Female (166 cm, 64 kg) | 46.35 kg LBM | 1,371 kcal/day | 2,125 kcal/day |
Boer (1984) Sex-Specific Lean Body Mass LBM (kg)
Evaluates 0.407 * Weight + 0.267 * Height - 19.2 for Men ("M") and 0.252 * Weight + 0.473 * Height - 48.3 for Women ("F").
=IF(OR(AND(B2 <> "M", B2 <> "F"), B3 < 120, B3 > 230, B4 < 30, B4 > 300), "Invalid Sex (M/F), Height (cm), or Weight (kg)", ROUND(IF(B2 = "M", 0.407 * B4 + 0.267 * B3 - 19.2, 0.252 * B4 + 0.473 * B3 - 48.3), 2))Katch-McArdle Basal Metabolic Rate (370 + 21.6 * Boer_LBM, kcal/day)
Substitutes Boer Lean Body Mass directly into 370 + 21.6 * LBM_kg.
=IF(OR(AND(B2 <> "M", B2 <> "F"), B3 < 120, B3 > 230, B4 < 30, B4 > 300), "Invalid Sex (M/F), Height (cm), or Weight (kg)", ROUND(370 + 21.6 * IF(B2 = "M", 0.407 * B4 + 0.267 * B3 - 19.2, 0.252 * B4 + 0.473 * B3 - 48.3), 0))Try the example
Use the original values or change them to test your understanding.