Which BSA formula should I use?

Follow your protocol or drug label. Mosteller is common in adults; Haycock is frequently used in children.

Yes — enter cm/kg or in/lb; values are converted internally before applying the equation.

Body Surface Area (BSA)

General Medicine Surgery & Trauma Critical Care Pediatrics

Medical context

Calculate body surface area with Mosteller, DuBois & DuBois, Haycock, or Gehan & George formulas. Compare all methods side by side.

Primary and hospital medicine teams use this for everyday internal medicine workflows.

This page explains the BSA formula, how to interpret the output, known limitations, and peer-reviewed references so you can verify results against primary sources and local protocols.

It is grouped under General Medicine because everyday internal medicine calculators.

How to use this calculator

Enter the values requested by the BSA calculator using the units shown beside each field.
Review the calculated result and read the interpretation section before acting on the output.
Check limitations and references if the result will change management, dosing, or disposition.
Use the related calculators section when you need supporting values (for example electrolytes, weight, or complementary risk scores).

Calculator

Units

Formula (primary result)

Height (cm)Weight (kg)

Result

1.818 m²

Mosteller

Mosteller: 1.818 m²
DuBois & DuBois: 1.81 m²
Haycock: 1.826 m²
Gehan & George: 1.831 m²
Using 170 cm · 70 kg

Educational use only. Confirm results with clinical judgment, primary sources, and local protocols. Not a substitute for professional medical advice. Full disclaimer.

Formula

Mosteller: √([Ht(cm)×Wt(kg)]/3600). DuBois: 0.007184×Ht^0.725×Wt^0.425. Haycock and Gehan formulas also available.

Interpretation

Mosteller is widely used for simplicity; DuBois is classic; Haycock is often preferred in pediatrics.

Limitations

BSA dosing must follow drug-specific references. Extreme body habitus reduces accuracy of all equations.

Frequently asked questions

Which BSA formula should I use?: Follow your protocol or drug label. Mosteller is common in adults; Haycock is frequently used in children.
Can I switch units?: Yes — enter cm/kg or in/lb; values are converted internally before applying the equation.
Is the BSA result enough to make a treatment decision?: No. Calculators support medical decision-making but do not replace examination, shared decision-making, institutional protocols, or consultant input when stakes are high.

References

Mosteller RD. N Engl J Med. Simplified BSA.
DuBois D, DuBois EF. 1916 BSA formula.
Haycock GB et al. Pediatric BSA.
Gehan EA, George SL. BSA estimation.