Mosteller1987 simplified equation
— m²Commonly used because the equation is simple and transparent.
Body size · Dosing support
Body Surface Area
Calculate Mosteller, Du Bois, and Haycock estimates together so you can match the method specified by the protocol or prescribing information.
Evidence recordSources and method currentVersion 0.1 · Updated July 17, 2026
Step 1
Enter height and weight
Private by design. Values are calculated on this device and are not saved or sent to analytics.
Step 2
Compare methods
Du Bois & Du Bois1916 historical equation
— m²Derived from a small historical sample; still specified by some references.
Haycock1978 infant-to-adult equation
— m²Developed from measured values spanning premature infants through adults.
No method is declared universally best.Use the BSA equation, dose cap, and rounding convention specified by the medication, protocol, or institution.
Evidence packet
What this tool is based on
This versioned record keeps the citations, equation or decision rule, units, test coverage, intended population, and exclusions attached to the tool.
How evidence review works →Mosteller equation · Primary publicationMosteller RD. Simplified calculation of body-surface area.N Engl J Med. 1987;317(17):1098. PMID: 3657876 ↗Du Bois equation · Primary publicationDu Bois D, Du Bois EF. A formula to estimate the approximate surface area if height and weight be known.Arch Intern Med. 1916;17:863–871. Reprint PMID: 2520314 ↗Haycock equation · Primary publicationHaycock GB, Schwartz GJ, Wisotsky DH. Geometric method for measuring body surface area.J Pediatr. 1978;93(1):62–66. PMID: 650346 ↗Adult comparison · Validation studyVerbraecken et al. Body surface area in normal-weight, overweight, and obese adults.Metabolism. 2006;55(4):515–524. PMID: 16546483 ↗
Intended population
Patients whose protocol, reference, or prescribing information requires an estimated body surface area.
Equation record
Mosteller, Du Bois & Du Bois, and Haycock equations displayed side by side.
Unit handling
Weight accepts kg or lb; height accepts cm or in. Calculations normalize to kg and cm and return m².
Test coverage
Published-equation examples, method comparison, unit equivalence, and invalid inputs.
Do not skip
Limitations and exclusions
- No formula is selected automatically; use the equation specified by the applicable protocol or labeling.
- The Du Bois equation was derived from a very small historical sample.
- Formula disagreement can become more important at body-size extremes and in very small children.
- A BSA result does not itself determine a drug dose, dose cap, or treatment plan.
- Verify height and weight timing and units before using the result in a clinical workflow.
One clearly labeled, contextually relevant sponsor may support this reference area. Sponsorship will never interrupt inputs, obscure results, influence formulas, or imply clinical endorsement.
About this tool
Body Surface Area (BSA) Calculator
Use this body surface area calculator to compare Mosteller, Du Bois, and Haycock BSA estimates from the same height and weight inputs.
Each published formula is calculated separately and labeled rather than blended into one result. Confirm which BSA method is expected by the medication, protocol, or clinical workflow.