What is considered the standard flush volume for modern toilets?

The standard flush volume for modern toilets is 1.6 gallons. This was established following changes in legislation in the early 1990s aimed at conserving water. The Energy Policy Act of 1992 mandated that new toilets must use no more than 1.6 gallons per flush (GPF). This flush volume is sufficient for effective waste removal while significantly reducing water usage compared to older models that typically used up to 3.5 to 7.0 gallons per flush. The design of modern toilets is optimized to achieve this efficient performance, making 1.6 gallons the industry standard for residential use. Additionally, advancements in toilet design, such as better flushing mechanisms and bowl shapes, allow this reduced volume to adequately perform the function expected without compromising on flush effectiveness.