A program to incorporate in any personal computer (microprocessor) with BASIC language, is herein proposed. This enables calculation of the expected values (50 percentile), and the range of "allowable" variables (3 and 97 percentiles) of the bicipital, tricipital and subscapular cutaneous skinfold thickness, and of the arm's circumference in 6 to 14-year-old boys and girls. It is easily modifiable so as to apply it to other population sectors, and also makes an anthropometric diagnosis. The program facilitates the handling and interpretation of some current biometric variables related to body composition, which are necessary for the full analysis of the actual nutritional status, both of individuals and of population groups.