Cartridge capacity is rated at 5 % coverage of toner on the page. Divide the price of the cartridge by its rated capacity in pages. For monochrome printers, the best price is around 1 cent per page and the worst about 5 cents per page. For colour laser printers, you need to add the cost of all four cartridges (cyan, magenta, yellow and black): the best price is about 12 cents per page and the price ranges upwards to over 30 cents per page for small, home/office models. If you want to print high quality graphics or if you want accurate colour matching, you should base your calculations on the cost of genuine toner cartridges rather than remanufactured.