Body Surface Area Calculator
Compute BSA using Du Bois, Mosteller, Haycock and other clinical formulas.
About Body Surface Area Calculator
Body Surface Area is used in oncology (chemotherapy dosing), cardiology (cardiac output normalisation), burn management (fluid resuscitation), and nephrology (GFR expression). The Mosteller formula is favoured in clinical practice because its form is simple enough to compute mentally or with a basic calculator. DEXA and 3D scanning give more accurate BSA, but formula-based estimates are adequate for most clinical dosing purposes.
Formulas
Mosteller
BSA = √(Height(cm) × Weight(kg) / 3600)
- H
- Height in cm
- W
- Weight in kg
Du Bois
BSA = 0.007184 × Weight^0.425 × Height^0.725
- H
- Height in cm
- W
- Weight in kg
Haycock
BSA = 0.024265 × Weight^0.5378 × Height^0.3964
- H
- Height in cm
- W
- Weight in kg
Gehan-George
BSA = 0.0235 × Weight^0.51456 × Height^0.42246
- H
- Height in cm
- W
- Weight in kg
Worked example
With the default values below, Body Surface Area Calculator returns Mosteller (1987) of 1.9365. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Unitsone of Metric (kg, cm), Imperial (lb, in)
- Metric (kg, cm)
- Weight (kg)accepts 1–300 kg
- 75 kg
- Height (cm)accepts 30–250 cm
- 180 cm
- Weight (lb)accepts 2.2–660 lb
- 165 lb
- Height (in)accepts 12–98 in
- 71 in
Results
- Mosteller (1987)Most commonly used in drug dosing protocols.
- 1.9365 m²
- Du Bois & Du Bois (1916)
- 1.9424 m²
- Haycock et al. (1978)Preferred for children and extreme body habitus.
- 1.9381 m²
- Gehan & George (1970)
- 1.9438 m²
- Average (all four)
- 1.9402 m²
Step by step
- 1Mosteller= 1.9365 m²
- 2Du Bois= 1.9424 m²
- 3Haycock= 1.9381 m²
- 4Gehan-George= 1.9438 m²
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- BSA calculations are estimates for informational and educational purposes. Drug dosing, cardiac output normalisation, and burn fluid resuscitation must be performed by qualified healthcare professionals using validated clinical protocols. This tool is not a substitute for medical advice.
- This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
BSA calculations are estimates for informational and educational purposes. Drug dosing, cardiac output normalisation, and burn fluid resuscitation must be performed by qualified healthcare professionals using validated clinical protocols. This tool is not a substitute for medical advice.
Frequently Asked Questions
Why are there multiple formulas?
Each formula was derived from a different patient population. Du Bois (1916) used nine healthy adults; Mosteller (1987) approximated several earlier formulas for clinical convenience; Haycock (1978) validated across infants to adults; Gehan & George (1970) used a large cross-sectional sample. For most adults in normal weight range they agree within 2–3%.
Which formula should I use for drug dosing?
Follow your pharmacy protocol. Mosteller is most widely used in modern oncology (e.g. ASCO BSA guidelines). Du Bois remains common in nephrology. Haycock is preferred for paediatric dosing.
What is a normal BSA for an adult?
The conventional reference BSA used in cardiac output normalisation is 1.73 m² (derived from the Du Bois formula for an average adult). In practice, typical adults range from 1.6 to 2.1 m², with men averaging about 1.9 m² and women about 1.7 m².