An image forming apparatus feeds a recording sheet from a sheet feed roller, clamps the recording sheet between an image carrier and a transfer roller, transfers a toner image to the recording sheet from the image carrier while conveying the recording sheet, and fixes the transferred toner image on the recording sheet. Recording sheets are stacked on an elevating plate. An elevating plate swinging mechanism vertically swings the elevating plate. A rotation drive mechanism rotates the sheet feed roller in synchronism with the elevating plate swinging mechanism. A recording sheet detector detects a leading edge of each recording sheet fed from the sheet feed roller. A conveyance controller measures sheet feed time from starting a sheet feed operation to detecting the leading edge of the recording sheet. Based on the measured sheet feed time, the conveyance controller sets a sheet feed start timing of a next recording sheet.