If you're self-employed and drive for work, the standard mileage rate is the simplest way to deduct the cost of your car. You multiply your business miles for the year by the IRS rate, and that's your deduction. For 2025 the business rate is 70 cents per mile, according to IRS Notice 2025-5. The rate changes most years, so check the IRS standard mileage rates page for the year you're filing.
Here's a worked example. Say you drove 6,240 business miles in 2025. At 70 cents, that's a $4,368 deduction. Business parking fees and tolls are deductible on top of that.
The deduction is easy to calculate. What trips people up is the record keeping. The IRS wants records made at or near the time of the trip, not a log reconstructed in March from memory. For each business trip, write down:
- the date
- where you went
- the business purpose, like "client meeting with Harper Dental" rather than just "meeting"
- the miles driven
You should also record your odometer reading at the start and end of the year. That gives you total miles, which matters because you'll report business miles and total miles on your return.
Not every drive counts. Commuting from your home to a regular workplace is personal, even if you take calls on the way. Driving from your office to a client site counts. Driving between two job sites in one day counts. If you work from a home office that qualifies as your main place of business, trips from home to clients usually count too, but it's worth confirming with a tax preparer if your setup is unusual.
For the miles column, don't guess. When you log a trip to a new address, use a calculator for the distance between two cities to get the actual road distance from where you started. For regular routes, check them once and reuse the number. A client you visit twice a month at 18.4 miles each way adds up to 883.2 miles over a year. Rounding that down to "about 15" each way would cost you 163 miles of deduction, or about $114 at the 2025 rate.
There's one timing rule to know. If you own the car and want to use the standard mileage rate, you generally have to choose it in the first year you use that car for business. You can switch to actual expenses in a later year, but going the other way has limits. If you lease, you have to stick with the standard rate for the whole lease once you pick it.
A paper notebook in the glove box works fine. So does a spreadsheet or an app. Keep the log with your tax records for at least three years after you file. If you ever get asked to back up the deduction, a plain, consistent log with dates and purposes is what holds up.
Top comments (0)