how many gallons of water does it take to flush a toilet
Asker's rating. 1  It depends on the design of the toilet. The newer ones can take as little as 1.4 gallons. 2  Some toilets have two flush functions. One short and one long. 3  The standard is 1.6 gallons for new toilets. They do make power flush toilets that have an air system added to them but use the same amount of water.