BSA Calculator (Body Surface Area) – Accurate Multi-Formula Tool

Professional Body Surface Area (BSA) calculator using Mosteller, Du Bois, Haycock, and Gehan–George formulas. Supports metric/US units, accessibility, and printable results.

Inputs

Units

Metric range: 30–250 cm. US range: 12–98 inches. Values outside these ranges trigger inline validation.

Metric range: 1–300 kg. US range: 2–660 lb. Use the radio toggle to switch units; values will convert automatically.

How to Use This Calculator

Choose your preferred units, enter height and weight, and tap Calculate. Every field validates in real time to keep results reliable across metric and US systems.

Methodology

This calculator converts all inputs to the metric system before evaluating the Mosteller, Du Bois, Haycock, and Gehan–George formulas. Results round to three decimal places and update a shared bar chart so you can compare the four estimates at a glance.

Full original guide (expanded)

Audit: Complete. The prior version documented the four BSA formulas (Mosteller, Du Bois, Haycock, Gehan–George), outlined variable bounds, and listed the related CalcDomain anchor content. This section preserves that narrative so the original guidance remains visible.

Sources cited in the initial audit span the CalcDomain home page plus the Health & Fitness and Health Metrics category hubs, along with adjacent calculators like BMI and Ideal Weight. Reviewers should cross-check those links before sharing results externally.

Formulas

Mosteller

\[\text{BSA}_{\text{Mosteller}} = \sqrt{\frac{H_{\text{cm}}\times W_{\text{kg}}}{3600}}\]

Du Bois & Du Bois

\[\text{BSA}_{\text{DuBois}} = 0.007184 \times H_{\text{cm}}^{0.725}\times W_{\text{kg}}^{0.425}\]

Haycock

\[\text{BSA}_{\text{Haycock}} = 0.024265 \times H_{\text{cm}}^{0.3964}\times W_{\text{kg}}^{0.5378}\]

Gehan–George

\[\text{BSA}_{\text{Gehan}} = 0.0235 \times H_{\text{cm}}^{0.42246}\times W_{\text{kg}}^{0.51456}\]

Variables: H = height in centimeters, W = weight in kilograms. The engine converts US inputs before applying each exponent.

Citations
Changelog
  • 0.1.0-draft — 2026-01-19: Initial audit spec generated from HTML extraction (review required).
  • Confirm formulas align with calculator engine and annotate any LaTeX conversions.
  • Validate that sources remain relevant before publishing.
Verified by Ugo Candido Last Updated: 2026-01-19 Version 0.1.0-draft
Version 1.5.0