The purpose of this study was obtaining values of basic inertial quantities of body parts including five parts of the trunk for young, fit living males. Thirty young, fit males (age: 24±4 years, height: 179±6 m, body mass: 74±7 kg) were directly measured (circumferences and skin-fat folds) and photographed in order to use these data for Clauser et. al. (parts of extremities) and Erdmann’s (parts of trunk) methods for estimation of mass and location of centres of mass of body parts. These methods take into account personal data for estimating inertial quantities. Relative mass (according to the mass of the whole body) of trunk parts (sum of thorax + abdomen + pelvis but without shoulder girdle) of subjects investigated in this work was similar to that obtained by Dempster for old cadavers. Relative mass differed for shoulders and for lower extremities. Old subjects for both lower extremities had around 31-32 % of the whole body mass and young subjects had almost 37 %.