A waste toner collecting device includes a waste toner container, a detector, and an auger. The waster toner container is to collect waste toner. The detector is to detect an amount of waste toner collected and accumulated in the waste toner container. The auger is to disperse the waste toner in the waste toner container. The auger includes a first blade to transport the waste toner in a first direction toward the detector in the waste toner container, and a second blade to transport the waste toner in a second direction opposite to the first direction in the waste toner container. The second blade includes a first blade section having a waste toner transport rate greater than a waste toner transport rate of the first blade.