Making information technology (IT) more accessible to elderly users is an important objective, in particular, concerning input devices. In this study, it has been investigated how the aging factor and the letter (character) size of a keyboard affects the efficiency in data entry. In addition, computer experience by the elderly was examined relative to efficiency. The performance measures (entry speed and correctly entered number per min) were twice better in a young group of computer users than in middle-aged and elderly groups. The effect of the size of the keyboard letters on performance was observed for the middle-aged and elderly groups who had no experience using a computer. The young, middle-aged, and elderly groups with computer experience were not affected by the size of the keyboard letters.