Enter your height and weight into the calculator to determine your estimated body surface area.

BSA Formula

The following formula is used to calculate your body surface area.

BSA = SQRT ( H * W / 3600 ) 
  • Where BSA is your body surface area (m^2)
  • H is your height (cm)
  • W is your weight (kg)

To calculate BSA, multiply your height by your weight, divide by 3600, then take the square root of the result.

This equation can be adjusted to use pounds and inches as the units as well. The calculator does this for you.

BSA Definition

BSA is defined as the total surface area of one’s body, also known as body surface area.

BSA Example

How to calculate BSA?

  1. First, measure your height.

    Measure your height and convert the units to cm.

  2. Next, measure your weight.

    Measure your weight and convert the units to kg.

  3. Finally, calculate your BSA.

    Using the formula above along with your height and weight, calculate your BSA.


What is BSA?

BSA stands for body surface area. It’s a measure of the total estimated surface area that a human body occupies based on height and weight. The formula was derived from averages over populations, so the exact surface area may vary.

What is a normal BSA?

There is no definite good amount of body surface area. Since muscle also increases size and surface area, sometimes a higher BSA is not bad. A better indicator of fitness and health is body fat percentage.

bsa calculator
bsa formula