Calculate your Body Surface Area (BSA) using the Mosteller formula, commonly used in medicine for drug dosing and clinical assessments.
Body Surface Area (BSA) is a calculated estimate of the total surface area of a person's body, expressed in square meters. It is primarily used in medicine — most notably for dosing certain medications, especially chemotherapy drugs, where dosing based on body surface area is considered more precise than dosing by weight alone.
This calculator commonly uses the Mosteller formula: BSA (m²) = √( (height in cm × weight in kg) ÷ 3600 ). The Du Bois formula is another widely used alternative: BSA = 0.007184 × height(cm)^0.725 × weight(kg)^0.425.
Enter your height and weight, and the tool calculates your estimated body surface area in square meters.
Example: For a person who is 170 cm tall and weighs 70 kg, the Mosteller formula gives BSA = √((170 × 70) / 3600) ≈ 1.82 m².
Why is BSA used instead of just weight for medication dosing? BSA correlates more closely with metabolic rate, cardiac output, and blood volume than weight alone, making it a more physiologically accurate basis for certain drug doses, especially in oncology.
Which formula is more accurate, Mosteller or Du Bois? Both are widely used and produce similar results; Mosteller is simpler to calculate, while Du Bois has been a long-standing clinical standard. Your specific medical context may dictate which is preferred.
What is a normal BSA range for adults? Average adult BSA is roughly 1.6 to 1.9 m², though this varies with height and weight.
Should I use this for self-medicating dosages? No — BSA-based dosing should always be calculated and confirmed by a healthcare professional, as this tool is for general informational reference only.
Does BSA change with age? Yes, BSA generally increases from childhood through adulthood as height and weight increase, then can gradually decrease slightly in older age with changes in body composition.