I literally kept track of all tax I paid on purchases for two years in a row by entering every receipt for EVERYTHING into Quicken, making a line-item entry for the item and a line-item entry for the actual tax paid on that sale. I then had a REAL sales-tax-paid amount for the year. Neither year did our REAL sales tax amount exceed their ESTIMATE. Their estimating formula always yielded the highest deduction. The only time your REAL sales tax paid will be more than their estimate is when you purchase one or more large ticket items in a given year (such as a boat or motor home). Otherwise, your bazillion shopping trips to Walmart, Target, Sam's Club, and Kohl's just won't ever add up to enough to use the REAL sales tax method. So, don't waste your time fooling with it if you don't have that one or two large ticket items that show a large sales tax. What you WILL need to know for TurboTax is your tax rate, which is often printed right on your cash register receipts. I shop in two main areas of the state (living in a rural area and going to two different areas for shopping). I just picked the tax rate for the city I shop in most and went with that in TurboTax.