A method for shifting a multi-speed transmission of a marine propulsion device between a first gear and a second gear each configured to transmit torque from a powerhead to a transmission output shaft. The method includes determining an actual power level requested for operating the marine propulsion device and measuring a transmission output shaft speed in which the transmission output shaft is rotating. The method further includes comparing the actual power level to a shift threshold, the shift threshold corresponding to expected power levels for operating the marine propulsion device as a function of the transmission output shaft speed of the transmission output shaft. The method further includes controlling the multi-speed transmission to shift when the actual power is outside the shift threshold.