An image reading device includes reading devices arranged in a main scanning direction perpendicular to a sub-scanning direction, position reference members each including a reference pattern for correcting relative positions of pixels in each of the reading devices or relative positions of the reading devices, and circuitry. The reference members move in the sub-scanning direction relative to the reading devices, and include first reference members for correcting the relative positions of the reading devices and second reference members for correcting the relative positions of the pixels in each of the reading devices. While switching between the first reference members and the second reference members, the circuitry calculates a correction value for a deviation of the pixels in each of the reading devices and a correction value for a deviation of the reading devices based on a result of reading of the reference members.