What Is Body Surface Area?
Body surface area (BSA) is an estimate of the outer surface of the body, reported in square metres (m²). In Greek this is often searched as επιφάνεια σώματος. Clinicians sometimes use BSA as a size index (for example in some dosing or physiology contexts). Pedzah’s BSA calculator is for education and comparison only — it is not a diagnosis and it does not replace a clinician’s measurement or judgment.
How Body Surface Area Is Calculated
This page uses the Mosteller formula, a widely cited BSA method that needs only height and weight. Enter centimetres and kilograms, or switch to feet/inches and pounds — the tool converts to metric before applying Mosteller. Other published BSA equations exist; Pedzah does not mix them on this page so the result stays traceable.
Body Surface Area Formula
Mosteller (1987):
BSA (m²) = √( height (cm) × weight (kg) / 3600 )
Example: 170 cm and 70 kg → BSA ≈ 1.82 m² using the same function as the calculator. The result is rounded to two decimal places.
BSA by Height and Weight
Taller height or higher weight increases estimated surface area, but not in a simple linear way — the square root compresses large changes. Two people with the same BMI can have different BSA if their height and weight pairs differ. BSA is not a body-fat measure and is not interchangeable with BMI or ideal body weight.
BSA Calculator Uses
People look up BSA as a size index, to understand textbook examples, or to compare height and weight together in one number. Some medical protocols use BSA; those decisions belong with a qualified professional and the formula they specify. Pedzah does not recommend medication doses.
Related body-size tools: body fat calculator and healthy weight range. Informational only — not medical advice. Results are estimates. Consult a qualified clinician for health decisions.