County-by-county listings for Ohio sales tax rates are available at Tax.Ohio.gov, according to the Ohio Department of Taxation. The listings, in black and white and color maps, show the state's 88 counties and their tax rates. The website offers a finder feature that locates sales tax rates by specific addresses.
Ohio law allows counties to change the rates of their sales taxes at the beginning of a calendar quarter, notes the Ohio Department of Taxation. Taxpayers can sign up to receive automatic notification by email when sales tax rates change. The department posts quarterly changes at its website as it receives them. Rate charts that show the proper tax for a specific tax rate and price are also available.