A sheet conveyance device includes a sheet placing portion, a guide member, a signal obtaining portion, and a notification portion. On the sheet placing portion, a sheet to be conveyed is placed. The guide member is disposed on the sheet placing portion so as to move in a width direction vertical to a sheet conveyance direction, and restricts, in the width direction, a position of the sheet on the sheet placing portion. The signal obtaining portion obtains an electric signal with a value corresponding to a position of the guide member. The notification portion, when a difference between the value and any of thresholds that are set in advance based on each sheet size in the width direction for determination of the size of the sheet, is equal to or smaller than a predetermined reference value, notifies that the sheet is separated from the guide member.