An image forming apparatus includes a conveying unit, an image forming unit, a fixing unit, a first driving unit, a second driving unit, a transmission unit to transmit an ultrasonic wave, and a reception unit. Where a determination is made that a timing at which excitation of the first driving unit is switched or a timing at which excitation of the second driving unit is switched overlaps with a timing to obtain a value of the ultrasonic wave received by the reception unit, the transmission unit does not transmit an ultrasonic wave. Where a determination is made that the timing at which the excitation of the first driving unit is switched or the timing at which the excitation of the second driving unit is switched does not overlap with the timing to obtain the value of the received ultrasonic wave, the transmission unit transmits an ultrasonic wave.