Note: This calculator is for City of Dayton residents only. Montgomery County residents can calculate their water bill at: -Montgomery County Sanitary Engineering (Going to their page will open a new browser) Enter your usage: (To calculate usage, subtract your last meter reading from your current reading) Select your meter size: (The most common residential size is 5/8") 5/8" 1-1.5" 4" 10" 3/4" 2" 6" 1" 3" 8" Return to the Water homepage Updated: 1-31-2007