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CalcSpectrum

Body Surface Area (BSA) Calculator

Calculate body surface area (BSA) in square meters from height and weight, using the Mosteller and Du Bois formulas.

Free to use · Instant results

Calculator Inputs

Enter your height, matching the unit selected below.

Enter your weight, matching the unit selected below.

Body Surface Area — Mosteller (m²)
1.82
Body Surface Area — Du Bois (m²)
1.81
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About these results

CalcSpectrum calculators produce automated estimates using established formulas and the specific values you enter. Because real-world outcomes depend on input accuracy, mathematical assumptions, and rounding conventions, please verify critical figures with an appropriately qualified financial, tax, medical, legal, or other professional, as relevant.

Health & Fitness Notice: Wellness and body metric calculations provide informational estimates based on generalized population formulas. They do not provide medical diagnosis, clinical advice, or treatment plans. Consult an appropriately qualified medical or healthcare professional for personal guidance.

How It's Calculated

Formula

Mosteller: BSA=height (cm)×weight (kg)3600Du Bois: BSA=0.007184×height (cm)0.725×weight (kg)0.425\text{Mosteller: } BSA = \sqrt{\frac{\text{height (cm)} \times \text{weight (kg)}}{3600}} \text{Du Bois: } BSA = 0.007184 \times \text{height (cm)}^{0.725} \times \text{weight (kg)}^{0.425}

Body surface area (BSA) estimates the total external surface area of the body from height and weight, in square meters. This calculator reports both of the two most widely used BSA formulas: Mosteller (1987), a simpler square-root formula, and Du Bois & Du Bois (1916), an older power-law formula still in routine clinical and pharmacology use (for example, normalizing renal function measurements or dosing certain medications). This is an estimate for general informational and educational purposes, based on a published formula — it is not a medical diagnosis, and it is not a substitute for individualized advice from a qualified healthcare provider. Neither equation is exact for any individual — both are population-derived approximations, and the two formulas will not produce identical results for the same height and weight. This calculator does not classify body size and does not average the two results, since the BRD-specified formula set reports them as two independent, verifiable outputs rather than a single blended number.

Worked Examples

180 cm, 80 kg

  1. Mosteller: sqrt((180 × 80) / 3600) = sqrt(4) = 2.00 m²
  2. Du Bois: 0.007184 × 180^0.725 × 80^0.425 ≈ 2.00 m²

170 cm, 70 kg

  1. Mosteller: sqrt((170 × 70) / 3600) ≈ 1.82 m²
  2. Du Bois: 0.007184 × 170^0.725 × 70^0.425 ≈ 1.81 m²

Frequently Asked Questions

Why do the Mosteller and Du Bois formulas give slightly different results?

They're two independently derived equations from different eras of anthropometric research, each fit to its own historical dataset. Neither is universally more correct — this calculator reports both rather than picking one or averaging them.

What is BSA used for?

BSA is commonly used in clinical and pharmacology settings to normalize measurements (such as kidney function) or to scale medication dosing relative to body size, rather than using weight alone.

Is this an exact measurement of my body surface area?

This is an estimate for general informational and educational purposes, based on a published formula — it is not a medical diagnosis, and it is not a substitute for individualized advice from a qualified healthcare provider. Both formulas are population-derived approximations from height and weight, not a direct physical measurement of your body.