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⚙ BSA & Ideal / Lean Body Weight Calculator
Body Surface Area, Ideal Body Weight, Lean Body Weight, and Adjusted Body Weight for clinical dosing
Body Surface Area (BSA)
BSA — Mosteller
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√(Wt × Ht / 3600)
BSA — Du Bois
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0.007184 × Wt⁰⋅⁴²⁵ × Ht⁰⋅⁷²⁵
BSA — Haycock
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0.024265 × Wt⁰⋅⁵³⁷⁸ × Ht⁰⋅³⁹⁶⁴
Ideal Body Weight (IBW)
IBW — Devine Formula
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IBW — Robinson Formula
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Lean & Adjusted Body Weight
LBW — Janmahasatian
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ABW (Adjusted BW)
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IBW + 0.4 × (TBW − IBW)
BMI (reference)
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Wt / Ht²
Weight Comparison
Actual Weight vs. IBW (Devine)
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Clinical Use Reference
| Measure | Primary Clinical Use |
|---|---|
| BSA | Chemotherapy dosing, burn surface area, cardiac index calculation |
| IBW | Ventilator tidal volume (6–8 mL/kg IBW), some antibiotic dosing, drug calculations in non-obese patients |
| ABW | Aminoglycoside dosing in obesity, heparin dosing in obesity (when TBW > IBW) |
| LBW | Drugs with limited distribution into adipose tissue; propofol induction dose, some chemotherapy |
Normal adult BSA: approximately 1.7–1.9 m² (varies by sex and body size).
IBW is derived from population studies and represents the statistically “ideal” weight for a given height.
Medical Disclaimer: These calculations are for educational and clinical reference purposes only.
Actual dosing decisions must be made by a qualified healthcare provider considering the full clinical picture.
