📐 Body Surface Area Calculator
Body surface area — the total skin area of your body in square meters — predicts drug metabolism and heart output better than weight alone, which is why hospitals dose chemotherapy and index cardiac measurements to it.
The DuBois formula from 1916 remains the clinical standard: a power-law mix of your weight and height. Enter both and the calculator returns your BSA instantly.
How to use this calculator
Enter your height in centimetres and weight in kilograms to get your body surface area.
- Enter your Height in the cm field.
- Enter your Weight in the kg field.
- Read the headline body surface area in square meters.
- Use it for the clinical contexts described below.
Frequently asked questions
Which formula does it use?
The DuBois formula from 1916: BSA equals 0.007184 times weight in kg to the 0.425 power times height in cm to the 0.725 power. At 175 cm and 70 kg that gives about 1.85 square meters.
What is BSA used for?
Doctors dose chemotherapy by it, index heart measurements to it, and estimate burn area with it. It predicts drug metabolism and cardiac output better than weight alone.
What is a normal value?
Most adults fall between about 1.6 and 2.0 square meters, with the average near 1.7 for women and 1.9 for men. Children are much lower, which is why pediatric dosing uses it.
Why not just use weight?
Because a tall lean person and a short heavy person can weigh the same while metabolizing drugs very differently. Surface area tracks metabolic mass more honestly than the scale.