Which BSA formula should I use?

Mosteller for adults. Haycock for paediatric calculations. Du Bois remains the historical reference.

Why are the numbers so close?

All four formulas were calibrated against the same physiological reality. Within typical adult ranges, they agree within ±3%.

No — they answer different questions. BSA is a clinical scaling factor; BMI is a body-composition screening tool.

Is this safe for chemotherapy dosing?

No — this is an educational calculator. Always defer to clinicians using validated, version-controlled tools.

Does BSA change rapidly?

Not in adults. BSA changes slowly with significant weight gain or loss; for children it scales with growth.

Body measurements · Clinical reference

Body Surface Area Calculator

BSA for medical dosing and clinical reference.

Your details

Height

Weight

BSA values are clinical references — for actual dosing, defer to your clinician.

Average BSA

1.82m²

Mosteller (1987)

Most widely used in clinical practice.

1.82 m²

Du Bois (1916)

The historical reference formula.

1.81 m²

Haycock (1978)

Suited to children and lower body weights.

1.83 m²

Boyd (1935)

Older, less commonly used.

1.83 m²

What is Body Surface Area?

Body Surface Area (BSA) estimates the total surface area of your body — useful clinically because many physiological processes (heart output, drug dosing, fluid resuscitation, dialysis) scale better with surface area than with weight alone.

The four most-cited formulas

Mosteller (1987) is the simplest and most widely used in clinical practice. Du Bois (1916) is the historical reference. Haycock (1978) is particularly suited to children. Boyd (1935) is the oldest and least commonly used today.

How clinicians use BSA

Chemotherapy and other narrow-therapeutic-index drugs are dosed per m² of BSA. Cardiology uses indexed cardiac output (CO/BSA). Burn assessments and dialysis flow are calibrated to BSA, too.

Limitations & caveats

BSA is an estimate — actual surface area cannot be measured non-invasively.
Formulas drift apart in extreme body types (very lean or very obese).
Not a wellness or fitness target — primarily a clinical reference.
Mosteller is the modern default; older formulas remain in some specialty literature.
For paediatric dosing, Haycock is often preferred.