Canonical: https://echosuite.app/guides/bsa/

# Body surface area calculator: height and weight

Calculate body surface area from height and weight, with explicit units and the formula supplied by the tool.

Created by [Mohammed Kamareddine, MD](https://echosuite.app/about/) · [Sources & educational scope](https://echosuite.app/about/)

[Open interactive calculator →](https://echosuite.app/calculators/#bsa)

## Method

Mosteller: BSA = √(height × weight / 3600)

Use the measurement units shown below. Some fields apply only to a selected method or condition; follow the interactive tool’s method choices. The interactive tool keeps missing measurements incomplete and provides its method-specific results and reference context.

## Measurements and acquisition

### Height · H  cm

Record the units, date and measurement source

- Use measured height and weight where feasible. Record the units, date and whether a value was reported or estimated.
- Fluid status and weight changes affect BSA. Document any substituted weight; do not silently replace measured weight with ideal or dry weight.
- Use the unit named by the field. BSA is in m²; height and weight can be converted in the Body surface area calculator. Keep the formula with serial indexed results.

### Weight · W  kg

Record the units, date and measurement source

- Use measured height and weight where feasible. Record the units, date and whether a value was reported or estimated.
- Fluid status and weight changes affect BSA. Document any substituted weight; do not silently replace measured weight with ideal or dry weight.
- Use the unit named by the field. BSA is in m²; height and weight can be converted in the Body surface area calculator. Keep the formula with serial indexed results.

### Formula

Record the units, date and measurement source

- Mosteller
- Du Bois
- Haycock
- Gehan & George
- Use measured height and weight where feasible. Record the units, date and whether a value was reported or estimated.
- Fluid status and weight changes affect BSA. Document any substituted weight; do not silently replace measured weight with ideal or dry weight.
- Use the unit named by the field. BSA is in m²; height and weight can be converted in the Body surface area calculator. Keep the formula with serial indexed results.

## Sources and method context

Primary BSA publications · Height–weight estimates of body surface area · Du Bois 1916 · Gehan & George 1970 · Haycock 1978 · Mosteller 1987

[Primary reference](https://pubmed.ncbi.nlm.nih.gov/3657876/)

- Mosteller · N Engl J Med 1987;317:1098 · doi:10.1056/NEJM198710223171717

BSA = √(H × W / 3600). H in cm, W in kg, BSA in m². The app defaults to this equation; this is not a claim that every echo reference uses it.

- Du Bois & Du Bois · Arch Intern Med 1916;17:863–871 · doi:10.1001/archinte.1916.00080130010002

BSA = 0.007184 × H^0.725 × W^0.425; H in cm and W in kg.

- Haycock, Schwartz & Wisotsky · J Pediatr 1978;93:62–66 · PMID:650346

BSA = 0.024265 × H^0.3964 × W^0.5378; H in cm and W in kg. The primary study included infants, children and adults.

- Gehan & George · Cancer Chemother Rep 1970;54:225–235 · PMID:5527019

BSA = 0.0235 × H^0.42246 × W^0.51456; H in cm and W in kg.

- Body size and indexed valve area · EACVI/ASE aortic stenosis focused update 2017 · section 1.3 · doi:10.1016/j.echo.2017.02.009

BSA indexing has limitations in obesity: aortic valve area does not grow in proportion to excess weight. Do not infer stenosis severity from an indexed value alone.

- Chamber indexing in obesity · Zong et al. JASE 2014;27:1267–1274 · PMID:25193637

The choice of body-size normalization affects recognition of left-heart enlargement in obesity. Retain raw measurements alongside indexed results.

Catalogue review status: Source mapped · clinical sign-off pending

These pages describe the educational tool. Interpret measurements with the complete clinical context and the method’s acquisition limitations.

## Keep exploring

- [Right atrial pressure assessment: IVC and hepatic vein flow](https://echosuite.app/guides/rap/)
- [Right atrial size calculator and measurement guide](https://echosuite.app/guides/ra-size/)
- [Right ventricular size calculator and measurement guide](https://echosuite.app/guides/rv-size-calc/)
- [Right ventricular function calculator: TAPSE, FAC and coupling](https://echosuite.app/guides/rv-function-calc/)
- [Left ventricular volumes and ejection fraction: a learning path](https://echosuite.app/learn/lv-volumes-ejection-fraction/)

[All echo guides](https://echosuite.app/guides/) · [Learning paths](https://echosuite.app/learn/)