This study aimed to investigate the effect of character size and display style on reading rate when reading a sentence displayed on a computer screen (digital reading). The participants in this study were 21 university students with normal vision. Character sizes varied with heights of 0.7°, 1.1°, 1.7°, and 2.6°. Display conditions included Zoom, Reflow, Linear, and EP (Elicited Visual Presentation). In the Zoom condition, the reading rate was found to be lower for character sizes of more than 1.7°. However, in the Reflow, Linear, and EP conditions, the reading rate was not affected by character size expansion.