Body Surface Area Calculator: The Complete Guide
Calculate your body surface area (BSA). Enter your height and weight in metric or imperial units to get your BSA in square metres using the widely used Mosteller formula.
Who the Body Surface Area Calculator is for
Clinicians, students, and patients who need a quick BSA for dosing or physiology.
How to use the Body Surface Area Calculator
- Type your values into the fields above — pick your currency or units where the calculator offers them.
- Results update automatically as you type; there's no submit button and nothing is sent to a server.
- Adjust any input to compare scenarios, then copy the result with a single click.
How it works
Mosteller formula: BSA (m²) = √(height(cm) × weight(kg) ÷ 3600). It's the simplest accurate BSA equation and the most common in clinical practice.
Features
- Mosteller formula
- BSA in square metres
- Metric or imperial
- Instant result
What body surface area is used for
Body surface area is the total area of the outside of the body, estimated from height and weight. Medicine uses it to dose certain drugs (especially chemotherapy), index cardiac output, and scale physiological measurements — because BSA often tracks metabolic needs better than weight alone. The Mosteller formula is the standard quick estimate.