A variable diameter discharge system for controlling the flow and distribution of a material being fed into a bin. The variable diameter discharge system generally includes a storage bin including a bin opening for receiving a material to be stored in the storage bin. A hopper is suspended beneath the bin opening such that materials fed into the bin opening pass through the hopper. A ring member is connected to the hopper which includes a plurality of guide members adjustable between a first position and a second position. An opening is defined between the guide members with the opening enlarging as the guide members are adjusted toward the second position. Springs connected between the guide members and the ring member bias the guide members toward the first position. The guide members move from the first position to the second position when a material is flowing through the opening.