The IRS uses specific rates for your particular zip code to arrive at your total sales tax rate. The local sales tax rates (such as city sales tax) can vary from town to town, and occasionally there are additional special local sales tax districts.
You can use the tool at the IRS website to get the specific total sales tax rate for your zip code (state and local sales tax rates).. If you wish, it will actually calculate your sales tax deduction as well, which you can compare to TurboTax.
Or if you just want to quickly get to the last screen to see the sales tax rates, you can just enter estimated or test values into the tool.
It IS important that you enter the correct zip code, however.When you go through the short interview, on the last page it will tell you your state sales tax rate and your local sales tax rate, which you can add to get your total sales tax rate.
https://www.irs.gov/credits-deductions/individuals/sales-tax-deduction-calculator
