Body Surface Area Calculator

Body surface area (BSA) estimates the total surface area of your body from height and weight. It's most commonly referenced in clinical settings — this tool is for general reference and education, not for calculating medication dosing.

Body Surface Area Calculator

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Height (cm)

Weight (kg)

Body surface area

2.00 m²

For general reference only — clinical dosing decisions should always be made by a healthcare professional.

The Mosteller formula

BSA (m²) = √[(height (cm) × weight (kg)) ÷ 3600]

Example

180 cm, 80 kg: BSA = √[(180 × 80) ÷ 3600] = √4 = 2.00 m².

Step-by-step guide

1. Enter your height and weight.
2. Read your estimated body surface area in square meters.

Common mistakes

Using this for any actual medication dosing decision — clinical dosing must be determined and verified by a qualified healthcare professional, not a general web calculator.

Mixing up centimeters with inches, or kilograms with pounds — the Mosteller formula requires metric units as shown.

Frequently asked questions

What is body surface area used for?

In clinical settings, BSA is sometimes used as a reference for certain medication dosing and for expressing measurements like cardiac output relative to body size. Any actual clinical use should be handled by a qualified healthcare professional.

Is the Mosteller formula the only one used?

No — several formulas exist (DuBois, Haycock, Gehan-George, and others), which can give slightly different results. Mosteller is popular for being simple to calculate while remaining reasonably accurate.

Can I use this instead of asking my doctor?

No — this is for general reference only. Any medical decision, including anything related to dosing, should be made by a qualified healthcare professional with your complete medical information.

Related calculators

See more in the Health Calculators section, or try the BMI Calculator and Ideal Weight Calculator.