Objectives: The measurement of VO2max is important for assessing the cardiovascular capacity of the body. Cardiovascular fitness is one of the factors affecting physical fitness and plays a key role in endurance exercise performance. However, measuring VO2max requires maximal exercise tests that may not be feasible to everyone. Hence, it is remarkable to find a method that can contribute to estimate VO2max without the need for physical activity and with the help of allometric equations. The purpose of this study was to determine the validity and reliability of the selected allometric equations for the measurement of VO2max (maximal oxygen uptake) in Iranian youth aged 18-25 years to calculate the maximal aerobic power of individuals. Methodology: The present study was conducted on 44 young male volunteers aged 18-25 years in Hamadan (Iran). After measuring the anthropometric variables, direct measurement of respiratory gases was used to measure VO2max and then to compare with the value obtained from selected allometric equations. Results: The current study aimed to determine the validity of three allometric equations for predicting VO2max specific to Iranian youth using the direct measurement of respiratory gases. The findings indicated potent correlation between the three VO2max prediction equations of Neville’s, VO2max = 0.244 × m0.699, Weibel’s, VO2max = 93 × m0.849 and Beunen’s, VO2max = 1.94 × m0.75 (R = 0.66-0.68, sig = 0.000) and direct measurement of aerobic power. Conclusion: Since easy calculation of VO2max is of great importance and weight can be measured easily in human research, especially in sports and healthcare centers, some of the allometric predictive models of VO2max using weight measurement as an alternative to physical activity may seem to be employed by studies related to epidemiology or cardiovascular health promotion, as well as by sports coaches at talent identification centers for young people. Also, due to the high correlation (R = 0.66-0.68) obtained from the direct measurement of respiratory gases and selected allometric equations, these can be used to estimate the aerobic power of young people with high validity and no longer need to boring maximal exercise tests.