Mileage Reimbursement Calculator (2026 Rates)

Multiply business miles by the IRS rate and you have a reimbursement number. The 2026 wrinkle is that there are two rates: 72.5 cents per mile for the first half of the year and 76 cents from July 1 onward, after a mid-year fuel adjustment. The calculator above handles the split; this guide covers the part software cannot, which is whether that reimbursement reaches the driver tax-free.

That question turns entirely on the accountable plan rules. The same dollar amount is either a tax-free expense reimbursement or fully taxable wages depending on whether the trips were substantiated with a real mileage log and any excess was returned. For an employer reimbursing a team, or an S-corp owner reimbursing themselves, the plan is worth more than the rate.

The output is business miles times the applicable 2026 rate, with the year split at June 30. It answers "what can be reimbursed or deducted for these miles," which is the ceiling for a tax-free accountable plan reimbursement and the amount a self-employed driver using the standard mileage method would deduct on Schedule C.

What it deliberately ignores: whether each trip qualifies as business travel, whether your records would survive an exam, parking and tolls (reimbursable separately, at cost), and whether the actual-expense method would beat the standard rate for your vehicle. The number is only as good as the log behind it.

An accountable plan is a reimbursement arrangement that meets three tests: expenses have a business connection, they are substantiated to the employer within a reasonable time (date, destination, business purpose, miles), and any advance beyond substantiated amounts is returned. Meet all three and mileage reimbursements at or below the IRS rate are excluded from the employee’s wages entirely: no income tax, no payroll tax, nothing on the W-2.

Fail any test and the arrangement is a nonaccountable plan: every dollar is wages, subject to income tax withholding and both halves of payroll tax, and the employee gets no offsetting deduction because unreimbursed employee expenses are suspended. A flat monthly "car allowance" with no mileage substantiation is the classic nonaccountable plan, and it quietly costs both sides payroll tax on money that could have moved tax-free.

Reimbursing above the IRS rate is allowed, but the excess over the standard rate is taxable unless actual expenses are substantiated. Most employers simply peg the plan to the IRS rate and update it when the IRS does, which in 2026 means updating twice.

The plan itself is not an IRS filing; it is a written reimbursement policy plus the discipline of following it. For a small business or a single-owner S-corp, setup is a one-afternoon project, and for the S-corp owner it doubles as the only mechanism that gets personal vehicle use reimbursed at all: adopt the policy in writing, submit real logs, cut real reimbursement payments, and book them as expense, not payroll.

• Adopt a written policy stating what is reimbursable (business mileage at the IRS rate, parking, tolls), who is covered, and the substantiation deadline.
• Require trip-level documentation: date, destination, business purpose, and miles, submitted within a reasonable period (60 days is a common written standard).
• Reimburse through accounts payable, separate from payroll, and never as a flat allowance.
• Require any excess advances to be returned within a stated window (120 days is the common written standard).
• Update the rate in the payroll and expense systems when the IRS changes it, which for 2026 means a mid-year update on July 1.
• Keep the submitted logs with the accounting records; the reimbursement is only as defensible as the paper behind it.

Vehicle expenses fall under the strict substantiation rules of IRC section 274(d), which is the part of the code where "close enough" does not work. On exam, mileage without adequate records is not negotiated down; it is disallowed, and courts routinely refuse to estimate vehicle expenses the way they sometimes estimate other costs. A reconstructed spreadsheet built from a calendar in the audit year carries little weight precisely because the rules demand records made at or near the time of the trip.

That standard is easier to meet than it sounds. A mileage app that runs in the background and asks you to swipe trips as business or personal produces a contemporaneous, timestamped log with almost no effort, and it captures the trip dates that a split-rate year like 2026 makes essential. A paper notebook in the glove box meets the standard equally well if it actually gets filled in; its failure mode is the three-month gap that ends the habit. Whichever tool you use, record the odometer at January 1 and December 31, because total annual miles are part of the required showing.

One more audit reality: round numbers invite questions. A log that produces 12,000.0 miles of business use and nothing else looks constructed; one that produces 11,847 miles across 214 dated trips looks like what it is. The best defense is boring, granular data collected as you go.

Commuting between home and a regular work location is personal, never reimbursable tax-free, no matter how far. Business miles are travel between work locations, trips to clients and job sites, business errands, and travel to temporary work locations. For a taxpayer whose home qualifies as their principal place of business, trips from the home office to other work locations count as business miles, which is why the home office question and the mileage question are usually answered together.

Locum physicians and multi-site professionals live in the gray areas: travel to a temporary assignment can be deductible business travel when the assignment is genuinely temporary and the tax home stays put. The rules are fact-specific enough that guessing is a bad plan; the miles are often large enough to be worth getting right.

Employees can only receive mileage value through an employer reimbursement; the personal deduction for unreimbursed employee mileage is suspended. Self-employed drivers take the standard mileage rate as a Schedule C deduction instead, or use the actual-expense method if it computes better. The same 72.5 and 76 cent rates apply either way, but the mechanism and the tax result differ.

If you are choosing between the standard rate and actual vehicle costs, that is a multi-year decision with depreciation consequences, covered in our mileage versus actual expenses guide. And the full rate history, including medical and charitable rates, lives on our IRS mileage rate page.