EBT2 film is a convenient dosimetry quality-assurance (QA) tool with high 2D dosimetry resolution and a self-development property for use in verifications of radiation therapy treatment planning and special projects; however, the user will suffer from a relatively higher degree of uncertainty (more than ±6% by Hartmann et al. [29]), and the trouble of cutting one piece of film into small pieces and then reintegrating them each time. To prevent this tedious cutting work, and save calibration time and budget, a dose range analysis is presented in this study for EBT2 film calibration using the Percentage–Depth–Dose (PDD) method. Different combinations of the three dose ranges, 9–26cGy, 33–97cGy and 109–320cGy, with two types of curve fitting algorithms, film pixel values and net optical densities converting into doses, were tested and compared. With the lowest error and acceptable inaccuracy of less than 3cGy for the clinical dose range (9–320cGy), a single film calibrated by the net optical density algorithm with the dose range 109–320cGy was suggested for routine calibration.