An image forming apparatus includes heating and pressurizing rotary members, and a speed control unit. In a first mixed job to be executed in a first mode and where a first recording material is to be initially conveyed and a second recording material is to be conveyed subsequent to the first recording material, the speed control unit sets a conveyance speed of the first recording material to a second speed based on acquired grammage information and sets a conveyance speed of the second recording material to a first speed based on the acquired grammage information. In a second mix job to be executed in the second mode and where the second recording material is to be conveyed subsequent to the initially conveyed first recording material, the speed control unit sets the conveyance speed of the first and second recording materials to the first speed based on the acquired grammage information.