BSA Calculator - Body Surface Area

Our BSA calculator can find the body surface area with just two inputs: weight and height!

In this short article, we will cover:

• How to calculate BSA;
• The BSA formula;
• What's the average body surface area; and
• More about BSA!

Keep reading to know more about this metric 👩‍⚕️.

BSA is the total surface area of the human body, a parameter widely used in medicine. For example, it is an accurate indicator of metabolic mass, and we can also use it to find the cardiac index.

Before calculating BSA, you can look at the average body surface area for different population groups to check if yours is within the average:

• Infants: 0.25 m²;
• Children of 2 years: 0.5m²;
• Children of 10 years: 1.14m²;
• Women: 1.6m²; and
• Men: 1.9m².

There are many different BSA formulas to find this metric. By default, our body surface area calculator shows the most widely used one, the Du Bois formula:

where:

• $W$ is your weight in kg; and
• $H$ is your height in cm.

You can check all other formulas below and check their results using the advanced-mode within the body surface area calculator:

• Mosteller formula: ${\footnotesize \text{BSA} = 0.016667\times W^{0.5}\times H^{0.5}}$;
• Haycock formula: ${\footnotesize \text{BSA} = 0.024265\times W^{0.5378}\times H^{0.3964}}$;
• Gehan and George formula: ${\footnotesize \text{BSA} = 0.0235\times W^{0.51456}\times H^{0.42246}}$;
• Boyd formula: ${\footnotesize \text{BSA} = 0.03330\times W^{0.6157 - 0.0188\times \log10{(W)}}\times H^{0.3}}$;
• Fujimoto formula: ${\footnotesize \text{BSA} = 0.008883\times W^{0.444}\times H^{0.663}}$;
• Takahira formula: ${\footnotesize \text{BSA} = 0.007241\times W^{0.425}\times H^{0.725}}$; and
• Schlich formula:
  • Women: ${\footnotesize \text{BSA} = 0.000975482\times W^{0.46}\times H^{1.08}}$
  • Men: ${\footnotesize \text{BSA} = 0.000579479\times W^{0.38}\times H^{1.24}}$

Only the Body formula differentiates itself from the rest by introducing a logarithmic function. Read more about these types of functions in the log calculator!