The forced vital capacity (FVC) is a reference measure for respiratory support and phonatory production. Objectives: 1) To obtain FVC data of the Portuguese population and 2) To propose a multiple linear regression model to predict the FVC for clinical practice. Methods: 195 subjects participated (97 men with 10-53 years old and 98 women with 11-50 years old). Weight, height and smoking habits were obtained. FV...