Calculate Body Surface Area using Du Bois and Mosteller formulas. Used for chemotherapy and medical dosing.
Calculate BSA for medical dosing.
The Body Surface Area (BSA) Calculator determines your total skin surface area, a measurement used extensively in medicine for calculating drug dosages, assessing metabolic requirements, and evaluating burn severity. BSA provides a more accurate measure of body size than weight alone because it accounts for height, making it superior for standardizing treatments across patients of different sizes.
BSA is particularly critical in oncology, where chemotherapy doses are typically calculated per square meter of body surface area rather than by weight. This approach accounts for the relationship between body size and drug metabolism, helping to ensure therapeutic effectiveness while minimizing toxicity. BSA is also used to calculate cardiac index (cardiac output per m²), renal function indices, and fluid replacement requirements in burn patients.
Multiple formulas exist for calculating BSA, with the Du Bois and Mosteller formulas being most widely used. The Mosteller formula is preferred for its simplicity while maintaining accuracy. The average adult BSA ranges from 1.7-1.9 m², with men typically having larger BSA than women. Extremes of height or weight may require special consideration in clinical settings.
Height in cm, Weight in kg. Result in m² (square meters).
| Category | Typical BSA (m²) | Notes |
|---|---|---|
| Newborn | 0.20-0.25 | Special pediatric dosing needed |
| Child (5 years) | 0.70-0.80 | Age-adjusted formulas available |
| Adolescent | 1.40-1.70 | Approaching adult values |
| Adult Female | 1.60-1.80 | Standard reference range |
| Adult Male | 1.80-2.00 | Standard reference range |
| Large Adult | 2.00-2.50 | May need dose capping |
A person 170 cm tall, weighing 70 kg: Mosteller BSA = √[(170 × 70) ÷ 3600] = √3.31 = 1.82 m². For a chemo drug dosed at 25 mg/m², dose = 25 × 1.82 = 45.5 mg.
Related tools: BMI Calculator for weight assessment, GFR Calculator for kidney function, and Creatinine Clearance Calculator for drug dosing.
Mosteller formula: BSA = √[(Height cm × Weight kg) ÷ 3600]. Du Bois: 0.007184 × Height^0.725 × Weight^0.425. Results in m². Average adult: 1.7-1.9 m².
BSA correlates with metabolic rate and drug clearance better than weight alone. Chemotherapy uses BSA to standardize doses. Example: 25 mg/m² × 1.8 m² = 45 mg dose.
Adult males: 1.8-2.0 m². Adult females: 1.6-1.8 m². Newborn: ~0.25 m². BSA increases with height and weight. Used for cardiac index, burn assessment, dialysis.