How are property taxes calculated in Alpharetta in 2026?

Alpharetta property tax starts with Fulton County setting a fair market value for the home, then billing tax on 40 percent of fair market value at the millage rate the county, city and school district each set for the year. The same assessed value can produce a different bill from one year to the next if any of those three millage rates change. Your county and city set that rate annually, so last year's bill is not a reliable guide to this year's. Ask the Fulton County tax commissioner for your current figure.