Health
Body Surface Area Calculator
Calculate body surface area (BSA) in m^2 from height and weight using the Mosteller, DuBois, Haycock, or Gehan-George formula for clinical dosing.
Patient details
Body surface area (Mosteller (1987, most common))
1.84 m²
Typical adult BSA is 1.6 to 2.0 m². This result is inside that range.
All four formulas for comparison
- Mosteller
- 1.84 m²
- DuBois & DuBois
- 1.85 m²
- Haycock
- 1.85 m²
- Gehan-George
- 1.85 m²
For information only. Not a substitute for clinical judgement or pharmacist review. Verify dosing against your local protocol.
Frequently Asked Questions about the Body Surface Area Calculator
What is body surface area (BSA)?
BSA is the total outer surface of your body, measured in square meters (m^2). Clinicians use it primarily for chemotherapy dosing because drug regimens written in mg/m^2 track metabolic capacity more reliably than weight alone. The calculator shows all four formula results side by side, each rounded to three decimal places.
Which BSA formula should I use?
Use whichever formula your institution's protocol specifies. Mosteller (1987) is the most widely used in adult oncology, and it is easy to verify: sqrt(height_cm x weight_kg / 3600). DuBois and DuBois (1916) is the original reference. Haycock (1978) is validated for infants and children. Gehan-George (1970) appears in some research contexts.
What is a typical adult BSA?
Most adults fall between 1.6 and 2.0 m^2. The traditional pharmacology reference value is 1.73 m^2, the same figure used to normalize kidney function as mL/min/1.73 m^2. Results outside that range are normal for people at the extremes of height or weight, and the calculator flags whether your result falls inside or outside that band.
Why do the four formulas give slightly different results?
Each formula was derived from a different patient population using different statistical methods and body-measurement assumptions. For a 70 kg, 175 cm adult all four agree within about 1%. Differences grow at the extremes, such as very small children or very large adults, which is why oncology and pediatric protocols specify a single formula rather than leaving the choice open.
Is this calculator a substitute for clinical judgment?
No. It is a math tool only. Chemotherapy dosing also depends on the drug's specific protocol, capped or banded dose limits, organ function, performance status, and pharmacist verification. Always reconcile the calculated BSA against your local protocol before any clinical use.