Surface area in children: a simple formula.

We retrospectively compared body surface area (BSA) using the Mosteller formula square root(H x (w/360)) and a simple weight-based BSA formula ([4Wkg+7]/ [90+Wkg]). The participants were 363 children who underwent cardiac surgery from 1991 to 2000. Their age ranged from 5 days to 18 years, weight ranged from 1.2 kg to 98 kg and height ranged from 38 cm to 178 cm. There was excellent correlation (r(2)=0.991) between Mosteller formula and the new formula (P < 0.001). We propose that the weight-based formula is easy to use and accurate. It can safely replace Mosteller formula and dispense the need for time-consuming calculations.