Estimate body surface area from height and weight and compare four established formulas side by side.
Your measurements
Measurements are converted to centimeters and kilograms before applying each formula.
Your estimate
| Formula | BSA |
|---|---|
| Mosteller | 1.82 m² |
| Du Bois & Du Bois | 1.81 m² |
| Haycock | 1.82 m² |
| Gehan & George | 1.83 m² |
What is body surface area?
Body surface area (BSA) is an estimate of the body’s external surface expressed in square metres. Clinical teams may use it to standardize physiological measurements and, in some settings, as one component of medication or treatment calculations.
Formulas included
The primary result uses the simple Mosteller equation: BSA = √(height in cm × weight in kg ÷ 3600). The comparison table also calculates the Du Bois, Haycock, and Gehan–George equations so you can see whether formula choice changes the estimate.
Why do the formulas give slightly different results?
Each equation was developed from a different study population and mathematical fit. Differences are usually small for many average-sized adults but can become larger at extreme heights or weights and in children.
Can I use this result to calculate a medicine dose?
Do not calculate, change, or administer a medicine dose from this page. Clinical dosing may require a specified BSA formula, dose caps, organ-function adjustments, laboratory results, treatment protocols, and independent professional verification.
Does BSA have a healthy range?
BSA describes body size; it is not a healthy-weight classification. Use BMI and other appropriate assessments if your goal is to evaluate weight or body composition.
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