Obesity is one of the risk factors for many metabolic and cardiovascular diseases. Vital capacity measurement is one of the health procedures to show lung function. Vital capacity can be predicted by knowing age and height. Vital capacity percentage shows the result of vital capacity in measurement compared with the predicted vital capacity. Sixty six healthy volunteers (n=66) are used in this study. The results show that vital capacity percentage are higher in normal-thin volunteers with % RBW (Relative Body Weight) < 90% than the normal-normal high weight volunteers with % RBW (Relative Body Weight) < 90-110%. If the findings are compared by using statistical methods, the results show no significance differences (p>0,05).