Florida will need an additional 1.9 billion gallons of potable water per day by the year 2020 to meet its projected needs. We estimate the state could save 186 million gallons per day (or approximately 9% of its future water needs) by replacing all inefficient toilets in the state with ultra low-flow toilets. We estimate the cost to replace all inefficient toilets in Florida would cost homeowners $988 million. We estimate homeowners would recoup their expenses ($175) in less than four years through reduced water use. The methodology used to estimate water savings and costs consisted of several steps. To estimate the number of inefficient toilets in the state, we use the number of single-family dwelling units in the 2000 U.S. Census. Houses built before 1994 were not required to be built with ultra low flow toilets. We calculated that one inefficient toilet would be replaced per dwelling unit. Thus, our estimates can be considered conservative. The data for the cost of replacing inefficient toilets, the amount of water saved per toilet, and the annual cost savings per dwelling unit came from the Hillsborough County toilet replacement program. To determine water savings we took the Hillsborough program's estimated water savings per toilet replaced, and multiplied it by the number of 1990 single-family dwelling units in the state. Formula: (households served x average persons per household) x (average savings per flush x number of flushes per person per day) = gallons per day of water saved. Includes tables.