What is estimated
Estimated body surface area from height and weight using Mosteller, Du Bois, and Haycock formulas.
Body Surface Area Calculator
Estimated body surface area
Enter your values, then calculate to see a verified result.
Reference range
How this result is calculated
A clear calculation path based on your inputs.
Inputs usedReview the information used for this result.
Full calculation and sourcesReview the equation, normalized inputs, assumptions, and version.
Versioned calculationFormula v1.0.0
Method
Mosteller is primary; formula disagreement is reported instead of silently choosing one answer.
Important boundary
This page does not calculate a medication dose. Clinical dosing requires the prescribed protocol and independent professional verification.
Normalize height and weightConvert to centimeters and kilograms.
175 cm and 70 kgCalculate three formulasRun Mosteller, Du Bois, and Haycock independently.
Do not merge them into an invented average.Inspect formula spreadCompare the highest and lowest results with Mosteller.
Small spread does not remove clinical verification.Interpretation
m2 is the Mosteller body-surface-area estimate.
Du Bois and Haycock remain visible so equation choice cannot disappear.
Do not calculate or adjust medication from this page.
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Related calculators and resources
Method and test recordFormula v1.0.0
- Recorded scope
- health-body-composition
- Publisher
- CalculatorGeek
- Recorded review date
- 2026-10-04
- Next source review
- 2027-10-04
- Definition fixtures
- 4 configured scenarios
- Published examples
- 4 shown below
Recorded method
Independently evaluate all three published formulas, compare reference values, verify unit conversion, and preserve the clinical protocol boundary.
These records describe the published model and reference tests. A test-case count is not a certification of every possible input or an independent specialist review. Editorial policy
Known limitations
- The formulas were derived and validated in different samples.
- Agreement can change at unusual body sizes.
- A BSA value alone is never a medication order or treatment plan.
- Pediatric and specialty protocols may require a specific formula and independent verification.
Method sources
- Mosteller (1987): Simplified calculation of body-surface area
- Haycock et al. (1978): Height-weight formula validated in infants, children, and adults
- Verbraecken et al. (2006): BSA formula comparison in adults
- Shuter and Aslani (2000): Du Bois and Du Bois revisited
Latest model update
2026-10-04 - Initial CalculatorGeek shared-system implementation with source-backed method, fixtures, content, and result journey.
Reference inputs and expected results
Up to 12 examples from the configured definition fixtures are shown. Expected values use the stated output units; invalid inputs are intended to be rejected.
| Case | Inputs | Expected result |
|---|---|---|
| adult reference | Height or recumbent length: 175 cm; Body weight: 70 kg | Mosteller BSA: 1.84466197 m2; Du Bois BSA: 1.84814302 m2; Haycock BSA: 1.84676818 m2 (allowed numeric tolerance: 1.0E-5) |
| imperial parity | Height or recumbent length: 68.897638 in; Body weight: 154.323584 lb | Mosteller BSA: 1.84466 m2 (allowed numeric tolerance: 0.0002) |
| small body Haycock reference | Height or recumbent length: 75 cm; Body weight: 10 kg | Haycock BSA: 0.463505 m2 (allowed numeric tolerance: 0.0002) |
| invalid weight | Height or recumbent length: 175 cm; Body weight: 0 kg | Reject invalid input: weight |
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On this page
What the Body Surface Area Calculator answers
Estimate body surface area with Mosteller and compare Du Bois and Haycock results from the same normalized height and weight.
Formula spread and the no-dosing boundary remain visible because a precise-looking BSA is still an estimate.
Start with the Health calculators hub when you need to choose a different body-measurement method.
How to use the Body Surface Area Calculator
- Enter measured height or recumbent length and current weight.
- Use any supported metric or imperial units.
- Read Mosteller as the primary educational result and compare the alternatives.
- Use only the formula and verification process required by the real clinical protocol.
For a complementary body-measurement workflow, use the BMI Calculator. Compare the different height-weight index.
Formula, variables and method
Mosteller: sqrt(height cm x weight kg / 3600).
Du Bois: 0.007184 x height^0.725 x weight^0.425.
Haycock: 0.024265 x height^0.3964 x weight^0.5378.
All results are in square meters.
To compare this method with a different input model, open the FFMI Calculator. Scale fat-free mass to height.
Worked examples and boundary checks
175 cm and 70 kg
Mosteller gives 1.8447 m2, Du Bois 1.8481 m2, and Haycock 1.8468 m2. The shared result keeps the small disagreement visible.
Pediatric boundary
The input range accepts small body sizes, but the actual care protocol controls formula choice, measurement method, rounding, and independent verification.
How to interpret the result
BSA estimates external body surface from height and weight. It does not directly measure surface area and is not a treatment recommendation.
- The formulas were derived and validated in different samples.
- Agreement can change at unusual body sizes.
- A BSA value alone is never a medication order or treatment plan.
- Pediatric and specialty protocols may require a specific formula and independent verification.
For another relevant cross-check, continue with the Lean Body Mass Calculator. Estimate non-fat body mass with named regressions.
Frequently asked questions
Which BSA formula should I use?
Use the formula required by the applicable protocol. This page treats Mosteller as the educational default and shows two alternatives.
Why do the formulas disagree?
They use different fitted samples, constants, and exponents.
Can I use this for chemotherapy or another drug dose?
No. A clinician or pharmacist must select the protocol, formula, caps, rounding, and verification steps.
Does the calculator support children?
The height and weight range does, and Haycock included infants and children, but pediatric use still requires the actual clinical protocol.
What does square meters mean here?
It is the estimated total body surface expressed in m2, not the floor area occupied by the body.
Primary sources and evidence limits
- Mosteller (1987): Simplified calculation of body-surface area
- Haycock et al. (1978): Height-weight formula validated in infants, children, and adults
- Verbraecken et al. (2006): BSA formula comparison in adults
- Shuter and Aslani (2000): Du Bois and Du Bois revisited
Sources were checked 2026-10-04. They establish the published method or measurement context; they do not turn an anthropometric estimate into a diagnosis, direct body-composition measurement, or treatment recommendation.