Body Surface Area: Medical Applications and How to Calculate It
Learn what BSA is, why doctors use it, and how Du Bois and Mosteller formulas compare.
Body Surface Area (BSA) might seem like an obscure measurement, but it is critically important in medicine. Doctors use BSA to calculate chemotherapy dosages, determine fluid resuscitation rates for burn patients, and assess cardiac output. Getting the dosage right can be a matter of life and death.
Our Body Surface Area Calculator computes BSA using both the Du Bois (1916) and Mosteller (1987) formulas.
When BSA Matters
BSA-based dosing is used because it correlates better with metabolic rate than body weight alone. A 200-pound person with lots of muscle metabolizes drugs differently than a 200-pound person with high body fat.
For a broader understanding of your body metrics, combine BSA with BMI, lean body mass, and body fat percentage. Your body type can also help contextualize these numbers.
Try the Calculator
Put these concepts into practice with our free Body Surface Area Calculator. No signup required.