Body Surface Area Calculator

Weight:  kg
Length:  cm
Surface Area:  m2

This calculator uses the formula of Haycock et al, which has been validated for the whole paediatric and adult population including extremely low birth weight infants.

Input the child's weight (in kg) and his or her length (in cm).

Calculator Algorithm:

Surface Area = W 0.5378  x L 0.3964  x 0.024265

The equation has two variables: weight in kg (W) , and length in cm (L).


Haycock GB, Schwartz GJ, Wisotsky DH.  Geometric method for measuring body surface area: A height-weight formula validated in infants, children, and adults. J Pediatr 1978;93:62-6.

Brion L, Fleischman AR, Schwartz GJ.  Evaluation of four length-weight formulas for estimating body surface area in newborn infants. J Pediatr 1985;107:801-3.

Contact this calculator's developers Last Modified 27 February 2019