Body Surface Area Calculator

Calculate body surface area (BSA) using the Mosteller and DuBois formulas. Used in medical dosing, chemotherapy, and burn assessment.

Part of our Health Calculators collection.

Body Surface Area Calculator

Free online calculator

Results update automatically as you type

How to Use This Calculator

  1. 1

    Enter weight in kg.

  2. 2

    Enter height in cm.

  3. 3

    See BSA in m² from both formulas.

BSA Formulas

Mosteller (most widely used in clinical practice):
BSA = √(Height(cm) × Weight(kg) / 3,600)

DuBois & DuBois:
BSA = 0.007184 × Height(cm)^0.725 × Weight(kg)^0.425

Average adult BSA: ~1.7–1.9 m²

Example Calculation

Example: 70 kg, 175 cm

Inputs

weightKg: 70heightCm: 175

Result

1.847 m² (Mosteller)

√(175 × 70 / 3600) = √3.403 = 1.845 m².

Frequently Asked Questions

When is BSA used in medicine?
BSA is used for chemotherapy dosing, cardiac output calculations, kidney function assessment (GFR), and pediatric medication dosing. It's considered more accurate than body weight for many drug dose calculations.
Which formula is most accurate?
The Mosteller formula is most commonly used in clinical practice due to its simplicity. DuBois is the historical standard but both are within 5% for most patients.

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Disclaimer: For reference only. All medical dosing decisions must be made by qualified healthcare professionals.