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Clinical calculator summary

Body Surface Area Calculator

An estimate of body surface area from height and weight using Mosteller or Du Bois equations.

Evidence-based context for fast calculator use

Purpose:
Support verification of medicines prescribed in mg/m²
Population:
Patients whose protocol uses body-surface-area-based dosing and has current measured height and weight
Factors:
Height, Weight, Selected equation, Protocol dose intensity
Reference:
Du Bois and Du Bois, Arch Intern Med. 1916; Mosteller, N Engl J Med. 1987
HomeBody Surface Area (BSA)
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Body Surface Area (BSA)

kg
cm

Clinical Context & Background

Body surface area is an estimate calculated from height and weight. This calculator implements the published Du Bois and Mosteller equations with weight in kilograms, height in centimetres, and output in square metres. Neither formula is universally preferred, no universal BSA cap is applied, and a calculated BSA is not itself a medication dose. Formula choice, dosing, and any protocol-specific cap must follow the relevant regimen and clinical context. Pediatric, very low-BSA, and extreme-body-size estimates require particular caution.
Primary Source EvidenceDu Bois D, Du Bois EF. Arch Intern Med. 1916;17:863-871. DOI 10.1001/archinte.1916.00080130010002. Mosteller RD. N Engl J Med. 1987;317:1098. DOI 10.1056/NEJM198710223171717.
Formula Logic
Du Bois: BSA = 0.007184 × weight(kg)^0.425 × height(cm)^0.725. Mosteller: BSA = √((weight(kg) × height(cm)) / 3600).

Reference Data

MethodEquation
Du Bois0.007184 × weight^0.425 × height^0.725
Mosteller√((weight × height) / 3600)

Clinical Workflow

Use, Interpret, And Continue The Patient Pathway

Expand for workflow guidance, limitations, examples, and related next steps.

When To Use

  • Use when a treatment protocol specifies dosing per square metre and current height and weight are available.
  • Use only when the patient and clinical setting match the population described for Body Surface Area Calculator.

How To Interpret

  • Mosteller and Du Bois estimates are usually similar but can diverge at body-size extremes.
  • Interpret thresholds with the entered units, current clinical status, and local guideline context.

What To Do Next

  • Multiply the verified BSA by the protocol dose and apply regimen-specific caps, rounding, organ adjustment, and independent checking.
  • Document the inputs, result, clinical judgment, and any reason for deviating from the model-guided pathway.

Limitations

  • BSA does not capture organ function, frailty, pharmacogenomics, toxicity history, or protocol-specific dose modifications.
  • This calculator supports clinical assessment and does not independently prescribe treatment.

Validated Population

Patients whose protocol uses body-surface-area-based dosing and has current measured height and weight

Clinical example

A patient 170 cm tall and 70 kg has a Mosteller BSA of about 1.82 m²; the final medicine dose still requires protocol and organ-function checks.

Calculation verification history

Verified

  1. : Production browser revalidation

    • Five source-backed Du Bois and Mosteller cases were exercised on the published route through visible controls; 5/5 expected values, formula labels, rounding, and pediatric caution matched.
    • No unexpected N/A, literal undefined value, stale control, or browser-console error was observed.
    Download latest production check (Excel)

    Case-level evidence is retained in validation/browser-revalidation/body-surface-area-calculator-2026-08-03.json.

  2. : Production browser validation

    • Ten source-backed cases were exercised on the public production route through visible browser controls; 10/10 case records passed their expected-versus-observed assertions across 11 visible submissions.
    • Overall browser status: failed-console. medium: Production emitted minified React error #418 during route loads/reloads used by this run.
    • Case-level inputs, expected and observed results, reset/repeat behavior, failure reproductions, and console evidence are retained in the production-browser evidence record.

    Case-level production evidence is retained in validation/browser-production/body-surface-area-calculator.json.

  3. : Full validation test

    • Passed 33/33 checks for both formulas, literal raw results, display rounding, decimal height and weight, exact keys, malformed values, and finite-input overflow.
    • Maximum raw difference was 4.996003610813204e-16 m² against a 1e-12 m² tolerance.

  4. : Correction

    • Now rejects missing, extra, nonfinite, nonpositive, overflowing, and unknown-method inputs.
    • Retains the full-precision raw BSA while displaying two decimals.
    • Removed the unsupported preferred-formula wording and did not impose an evidence-free maximum or universal BSA cap.

    Included in the current validation report.

Verification confirms the calculator implementation against the cited model; it is not independent clinical validation, regulatory approval, or medical advice.

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Frequently Asked Questions

What is Body Surface Area Calculator used for?

Support verification of medicines prescribed in mg/m². It is intended for patients whose protocol uses body-surface-area-based dosing and has current measured height and weight.

Does Body Surface Area Calculator determine treatment by itself?

No. Confirm the population, inputs, contraindications, competing risks, and current guideline recommendations before acting on the result.

Evidence-based oncology decision support. Verify with clinical guidelines.