Body Surface Area Calculator
Calculate your Body Surface Area (BSA) using the Mosteller formula, commonly used as a reference in medical dosing and clinical calculations.
How to use the Body Surface Area Calculator
- Enter your height in centimetres.
- Enter your weight in kilograms.
- Click Calculate.
- Read your BSA in square metres (m²).
Formula used
Worked example
Height 170 cm, weight 70 kg
170 × 70 = 11,900
11,900 ÷ 3600 = 3.306
BSA = √3.306 = 1.82 m²
Where BSA is used
Doctors use BSA to scale some chemotherapy doses, to index heart output (cardiac index) and kidney function, and in burn assessment. The average adult BSA is about 1.7–1.9 m². Mosteller is the simplest and most widely used formula; others such as Du Bois and Haycock give slightly different values. This calculator is for education and reference — medication doses must always be set by a qualified clinician.
Tips for accurate results
- Use current, accurately measured height and weight.
- Results for children differ widely by age.
- Do not use this result to adjust any medicine yourself.
Frequently Asked Questions
Around 1.9 m² for adult men and 1.6 m² for adult women.
Mosteller is widely accepted; differences between formulas are usually small for adults.
BSA tracks metabolic rate more closely than weight alone.
Related Calculators
Content reviewed by Vinod, Easy Smart Calculator · Last updated October 2026
Frequently Asked Questions
What is Body Surface Area (BSA)?
BSA is the estimated total surface area of the human body, commonly used in medicine for calculating drug dosages, especially in chemotherapy and pediatrics.
What formula is used to calculate BSA?
This calculator uses the Mosteller formula: BSA = √(height in cm × weight in kg / 3600), which is widely used for its simplicity and accuracy.
Is BSA the same for everyone with the same height?
No, BSA depends on both height and weight, so two people of the same height but different weights will have different BSA values.