BSA Calculator – Calculate Body Surface Area

What is a Body Surface Area (BSA) Calculator?

A Body Surface Area (BSA) Calculator is a medical tool used to estimate the total surface area of the human body based on height and weight. This measurement is vital in clinical medicine for determining accurate drug dosages, chemotherapy administration, fluid therapy, and nutritional assessment. By applying well-established scientific formulas, the calculator ensures precision in treatments where body size significantly impacts dosage safety and efficacy.

How the BSA Calculator Works

The BSA Calculator uses internationally recognized equations to compute your body surface area based on your height and weight. These equations have been validated in clinical studies and are routinely used in medical practice for drug and therapy calculations.

Our calculator provides results using multiple standardized formulas, including the Du Bois, Mosteller, Haycock, Boyd, Fujimoto, Takahira, and Schlich methods, offering a comprehensive medical overview across various clinical applications.

How to Use the BSA Calculator

1. Choose your preferred unit system (Metric or Imperial).
2. Enter your Height (in centimeters or feet/inches).
3. Enter your Weight (in kilograms or pounds).
4. Select your desired calculation method (e.g., Du Bois, Mosteller, Schlich).
5. Click Calculate to instantly view your BSA in m², ft², and in².

The calculator automatically applies your chosen formula and displays equivalent values in multiple measurement units for professional accuracy.

Popular BSA Calculation Formulas Explained

Each BSA formula serves a unique purpose in clinical and research settings. Understanding their basis can help you select the most appropriate one:

Du Bois Formula (1916)

One of the earliest and most widely used BSA equations:
BSA = 0.007184 × W^0.425 × H^0.725
Commonly applied in oncology and pharmacology.

Mosteller Formula (1987)

A simplified, reliable equation often preferred in clinical environments:
BSA = 0.016667 × W^0.5 × H^0.5

Haycock Formula (1978)

Designed for all ages, including pediatrics:
BSA = 0.024265 × W^0.5378 × H^0.3964

Schlich Formula (2010)

A gender-specific formula derived from 3D body scanning:
Men: 0.000579479 × W^0.38 × H^1.24
Women: 0.000975482 × W^0.46 × H^1.08

Why Knowing Your BSA is Important

1. Medication Dosing: BSA-based dosing improves drug safety and effectiveness, especially in chemotherapy and anesthesia.
2. Medical Assessments: Used to normalize physiological measurements like cardiac output, glomerular filtration rate, and metabolic rate.
3. Pediatric Care: Ensures precise drug administration in children, where weight-based dosing may be less accurate.
4. Clinical Nutrition: Helps estimate metabolic needs and caloric requirements based on surface area.
5. Research & Pharmacology: BSA is a critical parameter in pharmacokinetic modeling and comparative physiology studies.

Frequently Asked Questions About BSA

What is a normal BSA value?

For most adults, the average BSA ranges from 1.6 to 1.9 m². Values vary based on body size, gender, and ethnicity.

Which BSA formula should I use?

The Mosteller formula is widely used for general clinical purposes due to its simplicity and reliability, while the Du Bois and Schlich formulas are preferred in research and advanced pharmacology.

Why do doctors use BSA instead of BMI?

While BMI measures weight relative to height, BSA reflects total body area, making it more relevant for drug dosing, metabolic calculations, and physiological scaling.

Can I calculate BSA for children?

Yes. Formulas like Haycock and Boyd are validated for pediatric use, providing accurate results across different age groups.