Free Tool
How Much Mileage Are You Missing?
Most drivers forget 20 to 30 percent of their deductible trips. A quick run to the bank. A supply store stop between client visits. The trip you took on a Friday afternoon and never logged. Those forgotten miles add up to hundreds or thousands of dollars in unclaimed deductions every year.
Enter your driving habits below. This calculator estimates how much you are leaving on the table.
Suggests a starting estimate. Slide to your own number below.
Missed deduction this year
$1,131
1,560 miles × $0.725
- Total business miles per year
- 6,240
- Forgotten miles per year
- 1,560
- Tax cost (37% combined)
- $418
Over 3 years, that is
$1,255
You will never get back, unless you start tracking now.
Tax cost assumes a combined 37% rate (22% federal income tax + 15.3% self-employment tax). Your actual rate may differ. State tax savings are not included.
Trips people forget to log
The big trips are easy to remember. A 45-minute drive to a client meeting gets logged. It is the short, routine trips that slip through:
Errands between appointments. You stop at the office supply store on the way to a client. That detour is a business trip, but most people only log the client visit.
Bank and post office runs. Depositing a check or mailing an invoice for your business is a deductible trip. If you do it twice a week, that is over 100 trips per year.
Second and third stops in a day. You visit one client, then drive to another, then stop for supplies. The first trip gets logged. The second and third often do not.
End-of-day trips. A late afternoon meeting or a quick trip to drop off paperwork. By the time you get home, you have forgotten to record it.
Weekend work. Self-employed workers frequently drive for business on weekends, meeting a client, checking a property, picking up materials. These trips are deductible but rarely logged because they do not feel like "work."
The real cost of forgetting
At the 2026 IRS rate of 72.5 cents per mile, every forgotten trip has a dollar value. A 10-mile round trip to the bank is $7.25 in deductions. Forget that trip twice a week for a year: $754 in unclaimed deductions. At a combined 37% tax rate (22% income + 15.3% SE tax), that is $279 in unnecessary taxes, from one type of forgotten trip.
Scale that across all the small trips you miss, and the number grows fast. A driver who forgets 25% of their 15,000 annual business miles is leaving $2,719 in deductions unclaimed. That costs roughly $1,006 in taxes every year.
Over three years, that is $3,018 you paid to the IRS that you did not owe.
The fix
Automatic tracking eliminates the problem entirely. An app that detects when you are driving and logs every trip means nothing gets forgotten. You review and classify trips instead of trying to remember them.
If you prefer manual tracking, the key is consistency: log trips immediately, not at the end of the day. Set a reminder. Keep a logbook in your car. The goal is capturing every trip, not just the obvious ones.
FAQ
Where does the 20 to 30% estimate come from?
Industry surveys from mileage tracking companies consistently find that drivers who switch from manual to automatic tracking discover 20 to 30% more deductible trips than they were previously logging. The IRS Taxpayer Advocate has noted similar patterns in audit data, where claimed mileage often falls well below what business patterns would suggest.
Is it too late to claim miles I missed in previous years?
You can file an amended return (Form 1040-X) for up to three years after the original filing date. If you have records or can reconstruct evidence for missed trips, you may be able to recover past deductions. Consult a tax professional for your specific situation.
Does this calculator replace a mileage log?
No. This estimates what you are likely missing. To actually claim the deduction, you need a compliant mileage log with contemporaneous records of each trip. This tool shows you why keeping that log matters.
Stop leaving money on the table.
Track every mile automatically with TruMile. Free for 40 auto trips per month.
Download free on the App Store