The IRS provides Sales Tax Tables to help you estimate how much sales tax you can deduct. Credit Karma Tax uses these tables to help you calculate this deduction. The calculation uses both your income and the number of exemptions you take to approximate how much you can deduct. You’ll add the amounts given for both your state deduction and your local deduction.
If you’ve moved or want to get more specificity with local sales tax, the IRS also offers a Sales Tax Deduction Calculator to help you more accurately calculate that deduction.
You also may be able to add any sales tax for large purchases you have made like cars, boats, or home renovations.