An adjustable pedal assembly has a base, a beater assembly, and a pedal. The base has a pedal end and a beater end. The beater assembly is mounted on the beater end of the base. The pedal is mounted pivotally on the base and connected to the beater assembly, and has a stationary heel, an adjustment bracket, a moving sole and a rigid link. The stationary heel is mounted securely on the pedal end of the base. The adjustment bracket is mounted pivotally on the stationary heel. The moving sole is connected pivotally on the adjustment bracket and connected to the beater assembly. The rigid link is selectively connected the stationary heel and alternately to the adjustment bracket and the moving sole to change a pivoting point and swinging length of the pedal.