Objective: This study aims to evaluate the usefulness of the CompuDent program in determining the pre-operative volume of bone graft in maxillary sinus floor lifts, and to calculate the volume of graft necessary for rehabilitation using varying lengths of implants. Study design: Based on the CompuDent program, we calculated the volume of graft necessary for 47 sinus lifts. This volume was measured in order to raise the floor of each sinus to 13.4 and 15 mm in height. Results: The average volume of graft in order to achieve a lift of 13?4 mm was 2.42 cm³ for the right maxillary sinus, with a range from 1.4 cm³ to 4.1 cm³, and 2.50 cm³ for the left maxillary sinus, with a range from 1.04 cm³ to 3.79 cm³. The average volume of graft in order to achieve a lift of 15 mm was 3.01 cm³ for the right maxillary sinus, with a range from 1.78 cm³ to 4.59 cm³, and 3.09 cm³ for the left maxillary sinus, with a range from 1.42 cm³ to 4.49 cm³. The statistical results provided by the Pearson Correlation show a significant inversely proportional correlation between the average of the heights and the volume of graft in the sinus. In addition, there is a clear correlation between the average volumes to be grafted for the respective heights 13.4 mm and 15 mm. Conclusions: The CompuDent program is an effective tool in determining the volume of bone graft given its simplicity, rapidness and possibility of standardization in all pre-surgical procedures.