mileage rate for business use of a personal vehicle

[sbstrucking]

According to IRS Publication 463, the standard mileage rate in 2023 for deductible car expenses is $0.655 per mile. I entered 997 miles into TurboTax 2023. Simple arithmetic shows an allowable deduction for the mileage alone of $723.12. In spite of this, TurboTax 2023 calculates my total deduction (which apparently includes the business portion of my vehicle's property tax) as $655. There seems to be an error in the software for this particular calculation, which seems as if it might be based on the 2022 standard mileage rate of $0.585 per mile?

[AnnetteB6 · Accepted solution]

You are correct that the 2023 business use standard mileage rate is $0.655 cents per mile.  However, for 997 miles of business use and $0.655 cents per mile, the deduction would be $653.04.  

If you still believe there to be an error in TurboTax calculating the mileage deduction, please share whether you are entering the mileage as a Schedule C business expense or in another form so that we can take a closer look.

[sbstrucking]

Mea culpa. I use a self-designed spreadsheet to track my expenses and sum the year end totals. You're spot on on the arithmetic (and had I even given it a cursory glance, I'd have known what my spreadsheet was reporting was nonsense). GIGO, essentially, in that it turns out there's a logic error in the summation of this particular item. Thanks for taking time to respond.

[Mike9241]

your simple arithmetic is wrong 997*.655 is 663

723.12/997 = .725 cents per mile.

when using standard mileage the only other expenses that are included are business tolls (you can only enter the business portion - Turbotax does not prorate); business parking fees (same rule for tolls) and a portion of property taxes based on percent of business use. Property taxes must be based on value. flat fees are not included.

[sbstrucking]

Please note my reply above. The 723.12 was actually the correct deduction aggregated by my record keeping but the spreadsheet logic failed to aggregate a correct mileage. Again, if I'd done more than a cursory inspection of the two numbers next to one another I'd have seen the contradiction. Thanks for pointing it out again, though nevertheless unnecessarily.