ToolBark
Health & Fitness

Body Surface Area Calculator

Calculate your body surface area using Du Bois & Mosteller formulas

Unit System

Your Measurements

Result

Average BSA

1.846

Typical adult range
0.5 m²1.75 m²3.0 m²
< 1.6 m²1.6 – 2.0 m²2.0 – 2.2 m²> 2.2 m²

Formula Breakdown

FormulaBSA (m²)Equation
Du Bois1.84810.007184 × H0.725 × W0.425
Mosteller1.8447√(H × W / 3600)
Average1.8464(Du Bois + Mosteller) / 2

Clinical Context

  • Average adult female BSA ≈ 1.6 m²
  • Average adult male BSA ≈ 1.9 m²
  • BSA is used in oncology to dose chemotherapy drugs accurately
  • Also used to calculate cardiac index and kidney function (GFR) adjustments

For educational purposes only. Not a substitute for professional medical advice.

About

The body surface area (BSA) calculator estimates the total skin surface area of the human body using your height and weight. BSA is a critical metric in clinical medicine — oncologists use it to calculate chemotherapy doses, cardiologists use it to normalize cardiac output, and nephrologists apply it when estimating glomerular filtration rate. This tool supports both the classic Du Bois and the widely-used Mosteller formula.

FAQ
What is body surface area (BSA) used for?+

BSA is used clinically to dose medications — especially chemotherapy drugs — more accurately than body weight alone. It is also used to calculate cardiac index (cardiac output per m² of BSA) and to normalize kidney function metrics like GFR. The average adult BSA is about 1.7–1.9 m².

What is the difference between the Du Bois and Mosteller formulas?+

The Du Bois formula (1916) is the historical gold standard: BSA = 0.007184 × H^0.725 × W^0.425. The Mosteller formula (1987) is simpler and widely used in clinical practice: BSA = √(H × W / 3600). Both give very similar results for average adults; the Mosteller formula is slightly higher for heavier individuals.

What is a normal BSA for adults?+

A typical adult female has a BSA of approximately 1.6 m², while a typical adult male is around 1.9 m². Values between 1.6 and 2.0 m² are considered the normal adult range. BSA varies with body size and is lower in children and smaller adults.

Does BSA change with weight loss or gain?+

Yes. Because BSA depends on both height and weight, changes in body weight directly affect your BSA value. However, BSA is less sensitive to weight changes than BMI — a 10 kg gain in a 70 kg adult changes BSA by roughly 3–4%, whereas it shifts BMI proportionally more.

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