Surface area to body weight ratios were calculated for three age groups of the population using direct measurement data reported in the scientific literature. A strong negative correlation was observed between these ratios and age, and ratios did not differ as a function of sex. Distribution data for surface area to body weight ratios are presented for three age groups. Because of the strong correlation between these two factors, the use of these distributions in human exposure/risk assessments using point estimation techniques and/or Monte Carlo simulations may be more appropriate than treating surface area and body weight as independent variables.