The IRS standard mileage rate almost always changes once a year, on January 1. In 2026, it changed twice — and if your mileage log spans both halves of the year, using one flat rate for the whole thing will quietly get your deduction wrong.
What actually happened
The IRS set the 2026 standard business mileage rate at 72.5 cents per mile, effective January 1 — itself already up from 70 cents in 2025. Then, in a rare mid-year move, the IRS raised it again to 76 cents per mile, effective July 1 through the end of the year, citing rising fuel costs. Mid-year adjustments like this are uncommon; the standard rate normally holds steady for the full calendar year.
| Period | Rate per mile |
|---|---|
| 2025 (full year) | 70.0¢ |
| 2026, Jan 1 – Jun 30 | 72.5¢ |
| 2026, Jul 1 – Dec 31 | 76.0¢ |
Why this actually matters for your deduction
If you drove 3,000 business miles in the first half of 2026 and another 3,000 in the second half, the correct deduction isn't 6,000 miles at one flat rate — it's each half calculated at the rate that was actually in effect at the time.
| Approach | Calculation | Deduction |
|---|---|---|
| Using only the July rate (76¢) for all 6,000 miles | 6,000 × $0.76 | $4,560.00 |
| Using only the January rate (72.5¢) for all 6,000 miles | 6,000 × $0.725 | $4,350.00 |
| Correct: each half at its actual rate | (3,000 × $0.725) + (3,000 × $0.76) | $4,455.00 |
The difference between guessing wrong in either direction and getting it right is over $100 on just 6,000 miles — and it compounds the more miles you log, and the more evenly your driving is split across the two periods.
Why most quick calculators get this wrong
A calculator built once, with a hardcoded rate, is correct until the rate changes — and most tools don't get revisited every time the IRS updates a number, let alone when it updates it mid-year unexpectedly. The safest approach is to calculate mileage deductions per trip, applying whichever rate was actually in effect on that trip's specific date, rather than applying one number to a whole year's log at once.
What this doesn't cover
The standard mileage rate is a simplified alternative to tracking actual vehicle expenses — gas, insurance, depreciation, repairs, and so on. Whether the standard rate or actual expenses produces a bigger deduction depends on your specific vehicle and how much you drive for business versus personal use; a tax professional can help you compare both methods for your situation.
The Freelance Tax Deduction & Mileage Expense Estimator applies the correct rate automatically based on each trip's date, so a log spanning both halves of 2026 calculates correctly without you having to split it manually.