Body Surface Area Calculator

Calculate your BSA using multiple scientific formulas

Calculate Your Body Surface Area

Some formulas consider age for more accurate results

About Body Surface Area

Body Surface Area (BSA) is the measured or calculated surface area of the human body. It's widely used in medical practice for calculating drug dosages, assessing metabolic mass, and determining treatment protocols for conditions like burns and cancer.

Why BSA Matters

BSA provides a more accurate measurement than body weight alone for many medical purposes because:

  • It better correlates with metabolic processes
  • It accounts for both height and weight
  • It's less affected by body composition variations
  • It's particularly important for chemotherapy dosing

Standard BSA Values

The average BSA for adult men is about 1.9 m² and for adult women about 1.6 m². The "normal" BSA is generally considered to be 1.7 m² for a 70kg adult.

Common BSA Formulas

Dubois Formula

BSA = 0.007184 × height0.725 × weight0.425

Most widely used in clinical settings
Mosteller Formula

BSA = √(height × weight / 3600)

Simple and easy to calculate
Haycock Formula

BSA = 0.024265 × height0.3964 × weight0.5378

Often used for pediatric calculations
Gehan & George

BSA = 0.0235 × height0.42246 × weight0.51456

Used in some oncology protocols

Medical Uses of BSA

Chemotherapy

Drug doses are often calculated per m² of BSA to maximize effectiveness while minimizing toxicity.

Burn Assessment

The "Rule of Nines" uses BSA to estimate burn surface area for treatment planning.

Cardiac Index

Cardiac output is often normalized to BSA as cardiac index (L/min/m²).