Patent ID: 8649694

Claim:
An image forming apparatus comprising: image holding bodies that hold latent images by being subjected to exposure and hold toner images by being developed with toners; developer units that form toner images by developing the latent images held on the image holding bodies with toners; a transfer unit that transfers the toner images formed on the image holding bodies to a recording medium; a fixing unit that fixes the transferred toner images to the recording medium; a container mounting portion on which toner containers storing replenishing toners to be supplied to the developer unit are replaceably mounted; and a remaining toner amount calculating unit that calculates an amount of toner remaining in the toner container mounted on the container mounting portion, wherein the remaining toner amount calculating unit includes a primary calculator that calculates a plurality of primary remaining amounts by calculating the amount of toner remaining in the toner container on the basis of bases different from each other, respectively, a storage unit that stores empty area data of a remaining amount space where an empty area, where the toner container is empty, in a remaining amount space, which uses the plurality of primary remaining amounts as variables, is defined, and a secondary calculator that refers to the empty area data stored in the storage unit, and calculates a ratio of a distance between current coordinates and a point reaching the empty area to a distance between an origin and the point reaching the empty area on a straight line, which passes through the origin where the toner container is not in use and the current coordinates that are defined by the plurality of primary remaining amounts calculated in the primary calculator in the remaining amount space, as the current remaining amount of toner.