A walkthrough, end to end.
- 1
Enter your height and weight in metric (cm + kg) or imperial (ft·in + lb). The tool handles unit conversion internally.
- 2
Read your BSA in square meters. Two values show — DuBois and Mosteller — using different equations.
- 3
Use DuBois for physiology references and academic work. Mosteller is simpler arithmetic and is what most clinicians use bedside for chemo dosing.
DuBois & Mosteller formulas
DuBois & DuBois (1916) is the original BSA formula and still appears in most physiology references. Mosteller (1987) is mathematically simpler and easier to compute by hand — clinicians often prefer it for that reason. Both produce values usually within 3% of each other.
What you can do with this.
BSA for chemotherapy dosing
Most chemotherapy regimens dose by BSA in mg/m². Different institutions standardize on DuBois, Mosteller, or Haycock — the result can differ by a few percent. This calculator is for reference only; the dose should always come from your oncology team using their institution's standard.
BSA for cardiac index
Cardiac index (CI) is cardiac output divided by BSA, in L/min/m². It allows comparison of cardiac performance across body sizes. DuBois is the formula traditionally used in this context.
DuBois vs Mosteller — which to use?
DuBois is older and more often cited in textbooks. Mosteller is simpler, faster to compute, and is the bedside formula in most US hospitals. Difference between them is rarely more than 3%; for most clinical decisions either is fine.
Estimating glomerular filtration rate (GFR)
Some GFR estimating equations adjust to a standard 1.73 m² BSA for clinical reference. Knowing the patient's actual BSA lets you back-calculate to absolute GFR if needed.
Pediatric BSA
BSA scales differently in children — the same formulas apply but kids have proportionally larger BSA per kg of weight. For very young children, Haycock or Boyd formulas may be more accurate; this calculator uses DuBois & Mosteller (adults).
Body surface area in sports nutrition
BSA correlates with metabolic rate and heat dissipation. Some sports-physiology models use BSA-normalized values to compare athletes of very different body sizes — useful for endurance training prescription.
BSA calculator 2026 — what's current
DuBois (1916) and Mosteller (1987) are still the most-cited BSA formulas in 2026. What's evolved is recognition that for very obese patients, alternative formulas (like the Yu formula) may be more accurate — but DuBois and Mosteller remain the standards in most institutional dosing protocols. This calculator returns both for cross-reference.
Frequently asked.
All three commonly-cited formulas (DuBois, Mosteller, Haycock) agree within ~3%. There's no single 'most accurate' formula — institutions standardize on one and stick with it. DuBois is most cited academically; Mosteller is most used bedside.
Adult BSA typically ranges from about 1.5 m² (small adult) to 2.2 m² (large adult). The 'standard' reference body in many calculations is 1.73 m². Athletes and very tall people commonly exceed 2.0 m².
No. BSA-based chemo doses should always be calculated by your oncology team using your institution's standard formula. This calculator is for educational reference.
Not directly — the formulas use only height and weight. Men and women of the same height/weight get the same BSA. Body composition (more lean mass vs fat at the same BSA) does affect related calculations but not BSA itself.
No. Every calculation runs in your browser. There's no server processing, no analytics on inputs, no cookies storing what you typed.
It correlates with metabolic rate, heat dissipation, and drug clearance. In sports physiology, BSA-normalized values let you compare athletes of very different sizes. In clothing/wearable design, it informs sweat-rate estimates.