Describe a trip in your own words. AI logs it at the current IRS rate and builds a compliant record instantly, so mileage and taxes stop being a March problem. No GPS.
The mileage deduction is one of the largest tax breaks available to self-employed workers — and most people underestimate how fast it compounds.
The deduction reduces your Schedule C net profit — which lowers both your income tax and your self-employment tax. At a combined rate of roughly 35–40%, every $1,000 in mileage deductions puts $350–$400 back in your pocket. Drive 15,000 business miles and you're looking at an $11,400 deduction.
The catch is the IRS requires a contemporaneous log — a record kept at or near the time of each trip. A mileage estimate assembled in April is not a log. Without one, the deduction is at risk.
Most mileage tools make you tap start, drive, tap stop, and classify the trip afterward. FuelMath skips all of that.
Five things, every trip. FuelMath captures all five automatically. If you've been logging in a spreadsheet, check whether your records include each one — or start from our free IRS mileage log template.
Background GPS tracking is the default approach because it requires nothing from the driver. It works — but it comes with real trade-offs your deduction doesn't require you to accept.
Trips, miles, and dollars total up as you go. Watching the deduction climb is what turns logging from a chore into a habit — and the habit is what makes the record hold up.
Each trip you log becomes a dated line item — origin, destination, purpose, miles, and the dollar value at the current IRS rate — and the running total at the top is the deduction those lines are worth. At tax time you export the whole year to PDF or CSV and hand it to your accountant, already formatted. That's the whole loop: log as you drive, let it accumulate, file from a record you didn't have to reconstruct.
Every business mile logged and every IRS deduction calculated is free — no trip limits. Pro adds the complete picture.
Everything below builds on this page — the rate, the log, the forms, and the edge cases that decide whether a mile counts.