How Much Water Does a Low Flush Toilet Use?

A low flush toilet uses much less water than a conventional toilet, saving you money on your water bill and saving water for the environment. A conventional toilet uses from 3 to 5 gallons of water, depending on its age. Since 1994, all low-flush toilets have been made to only use 3 gallons per flush. In a compost low flush toilet, even less water is needed. A compost low flush toilet only uses between 1 pint to a ½-gallon of water to flush, depending on the type of compost toilet being used.