BSA Body Surface Area Calculator

Calculate body surface area for medical dosing and standardization

Última actualización: 2026-05-13

Última actualización: 2025-10-01

Basic Information

age

gender

Weight (kg)(kg)

Height (cm)(cm)

Select Calculation Formulas

Du Bois Formula

Most classic and widely used formula

Mosteller Formula

Simplified and accurate formula

Haycock Formula

Suitable for children and adults

Gehan & George Formula

Based on large sample data

Boyd Formula

More complex but precise formula

Body surface area formulas

This calculator compares common body surface area equations used to normalize clinical measurements and medication dosing decisions.

Du Bois BSA = 0.007184 x weight(kg)^0.425 x height(cm)^0.725
Mosteller BSA = sqrt((height(cm) x weight(kg)) / 3600)
Haycock BSA = 0.024265 x weight(kg)^0.5378 x height(cm)^0.3964

weight: Body weight; Converted to kilograms before the selected formula is applied.
height: Body height; Converted to centimeters before the selected formula is applied.
BSA: Body surface area; Reported in square meters and rounded for display.

How this BSA calculator works

Body surface area is an estimate, not a direct measurement. The selected equation, patient measurement quality, and local clinical protocol can all change how the result should be used.

Convert height and weight into the units required by each equation.
Apply the selected BSA equation and round the result for display.
Show formula comparisons when multiple equations are selected so clinicians can see the spread between methods.
Use the result as a reference value only; medication dosing and treatment decisions should follow local protocols and clinician review.

Important notes

BSA equations may diverge for infants, very small adults, severe obesity, edema, amputations, and other body-composition edge cases.
For chemotherapy, pediatric dosing, renal dosing, or critical-care use, verify the equation required by the institution or drug label.
A rounded BSA value can materially affect dosing when narrow therapeutic windows are involved.

Sources

Medical disclaimer

This BSA calculator is for educational and reference use only. It does not replace clinician judgment, institutional dosing policy, drug labeling, or patient-specific medical review.

Medical Disclaimer

This calculator is for clinical reference only. Dosage decisions should be verified by a qualified healthcare professional.