A recording medium determination apparatus that determines grammage of a recording medium by using an ultrasonic wave includes a transmission unit configured to output an ultrasonic wave having a predetermined frequency, a reception unit configured to receive the ultrasonic wave output from the transmission unit and transmitted through the recording medium and output a received signal, a calculation unit configured to calculate a signal having a peak component according to a cycle of the received signal, and a determination unit configured to determine the grammage of the recording medium based on the signal calculated by the calculation unit.