R. D. Mosteller

R. D. Mosteller authored the 1987 letter Simplified calculation of body-surface area, associated with the Mosteller formula for estimating body surface area from height and mass.^[ref] The published initial-only identity is retained.

The official VA technical manual records the unit-specific equationwhere height is in centimetres and body mass in kilograms.^[ref] It is an empirical estimate of area, not a direct measurement of the skin's complete geometry.

For an original arithmetic example, height 180 cm and mass 80 kg give $\sqrt{180\times 80/3600}=2$ m${}^2$. Entering 1.8 as though metres were the required input would instead give 0.2 m${}^2$: a hundredfold change in the numerical height becomes a tenfold change after taking the square root. The unit convention is therefore part of the formula, not an optional label.

A small-error calculation givesThis describes sensitivity to input errors within the equation; it does not quantify the empirical model's accuracy for a particular person. Area estimates can also enter derived quantities such as cardiac index, defined as cardiac output divided by body surface area. For stipulated output 5 L/min and area 2 m${}^2$, that ratio is 2.5 L/(min m${}^2$). A normalization changes the stated quantity; it does not create an additional direct flow measurement.