Your Calendar Is Already a Mileage Log: the 10-Minute Tax Deduction
Somewhere in your calendar, sitting between the dentist and next week's staff meeting, there is a tax deduction most business owners never collect. Not because it is complicated. Because nobody keeps the log.
Here is the number that should get your attention. Every mile you drive for your business right now earns a 76-cent deduction on your federal taxes. Two cross-town client visits a week quietly builds a four-figure deduction by December. If you run your own business and your work involves driving to clients, vendors, job sites, or networking events, that money is yours. You just have to keep the records the IRS asks for.
And here is the part almost nobody notices: if you book appointments on a digital calendar, you have been keeping most of those records all along.
What the IRS actually wants
The rules come from IRS Publication 463. For every business trip you deduct, your records need four things: the date, the destination, the business purpose, and the miles. The records also need to be timely. The IRS expects a log kept at or near the time of the trip, and Publication 463 explicitly treats a weekly log as timely. A spreadsheet reconstructed in April from memory is exactly what gets deductions denied.
Now look at any client meeting on your calendar. The date is there. The location is there. The title tells you who you met and why. That is three of the four required records, time-stamped the moment you booked the meeting, sitting in a system you already maintain without thinking about it.
The only thing missing is the miles. A maps app fills that in.
The three habits
The system runs on ten extra seconds at booking time.
First, put the real address in the Location field. "Sam, Copper Kettle Coffee, 1200 S Main St" beats "coffee with Sam." Your future self, and your tax preparer, will thank you.
Second, tag your business events. Pick a short marker, your company initials work fine, and put it in the title of every in-person business event. The tag is what keeps your personal appointments out of your tax records.
Third, close out each week in about ten minutes. Open last week's calendar, find the tagged in-person events (video calls do not count, nobody drove), pull the round-trip driving distance from your maps app, and enter one row per trip: date, purpose, destination, miles. Done weekly, that log meets the IRS timeliness standard.
What a mile is worth in 2026
The IRS did something this year that many owners will miss: it raised the rate mid-year. Trips from January 1 through June 30, 2026 are worth 72.5 cents per mile. Trips from July 1 onward are worth 76 cents. If your log applies one flat rate to the whole year, you are either shorting yourself or overclaiming, and neither is a good look. A good log applies the rate by trip date. The free template below does it automatically.
For scale: 5,000 business miles spread across 2026 is roughly a $3,713 deduction with both rates applied correctly.
One more thing your tax pro should weigh in on
The per-mile rate is optional. You are allowed to deduct your actual vehicle costs instead: fuel, insurance, repairs, depreciation, multiplied by the share of your driving that was business. On a newer or pricier vehicle, actual expenses is often the bigger number. Two things matter before you choose. The method you use in a car's first business year locks in your options for later years, so ask your tax professional before deciding. And whichever method wins, you still need the mileage log, because the business-use percentage that multiplies every actual cost comes from your mileage records. The log is the foundation either way.
A few boundaries, plainly stated: commuting to a regular office generally does not count, though trips from a qualifying home office to clients and job sites generally do. W-2 employees generally cannot take this deduction at all. And none of this is tax advice; your tax professional knows your situation.
[H2] The bottom line
Ten minutes a week, using a calendar you already keep, turns into a mileage record your tax preparer will accept. The deduction was always there. The record is the only thing that was missing.
Prefer zero minutes a week instead of ten? The whole pipeline can run fully automatic: calendar in, finished log out. That is how ours runs, and it is a fifteen-minute conversation.
