How mileage reimbursement works
The IRS standard mileage rate is not a gas allowance. It comes from an annual study of the full cost of running a car: fuel, yes, but also depreciation, insurance, maintenance, and tires, which is why it is so much higher than what the trip's gas cost. One number, applied per mile, settles all of it without receipts for every oil change.
2026 needs one extra sentence of care: the IRS raised the business rate mid-year, from 72.5 cents to 76 cents on July 1 (Announcement 2026-11, a response to fuel prices). The rate that applies is the rate on the day you drove, not the day you filed the expense report. This calculator carries both halves, and a full-year mode that splits your miles across them, because a year-end total priced at a single rate is quietly wrong in a year like this one.
The formula
For 2026: business miles at 72.5 cents through June 30 and 76 cents from July 1; medical and military-moving miles at 20.5 then 23.5 cents; charitable miles at a statutory 14 cents all year. Parking fees and tolls are reimbursed at actual cost on top of the rate; they are not baked into it.
Worked example
A consultant drives 340 miles to client sites in September 2026 and pays $18 in parking. At the current 76 cent rate: 340 × $0.76 = $258.40, plus $18 = $276.40 on the expense report.
A self-employed designer logs the whole year for the tax return: 6,200 miles from January through June and 5,800 miles from July through December. The halves price separately: 6,200 × $0.725 = $4,495.00 and 5,800 × $0.76 = $4,408.00, so the deduction is $8,903.00. Pricing all 12,000 miles at 76 cents would claim $217 too much; at 72.5 cents it would leave $203 on the table.
Commuting, records, and paying above or below the rate
The rule that surprises people most: the drive from home to your regular workplace is never reimbursable or deductible, no matter how long it is. Commuting is a personal cost. The miles that count start once work does: office to client, client to client, or home to a client site if your home is your principal place of work. An expense report that starts the odometer in the driveway for a trip that began at the office is the most common honest mistake in mileage logs.
The record the IRS expects is simple but contemporaneous: date, destination, business purpose, and miles, kept as you go rather than reconstructed in April. A dated calendar entry plus the miles is enough; a year-end guess is not.
Employers are not required to use the IRS rate, or federally to reimburse mileage at all, though some states (California, Illinois, and Massachusetts among them) require reimbursement of actual vehicle expenses. Paying less than the rate is legal in most states; the gap simply goes unreimbursed, and employees generally cannot deduct it on a federal return. Paying more works too, but the excess above the IRS rate is taxable wages even under an accountable plan, which is why this calculator prices the excess for you the moment your custom rate goes over 76 cents.
Your next step: the log is the money
Every dollar this page computes rests on one record: a mileage log kept at the time of driving, because the IRS standard for substantiation is contemporaneous, and a log reconstructed in April protects nothing. The format is your choice, and both ends of the spectrum work: an automatic GPS mileage-tracking app that logs every drive and lets you swipe business or personal, or a notebook in the glovebox with date, destination, purpose and odometer. What matters is that it exists before anyone asks for it. Start it today, with today's odometer reading, and this calculator's answer becomes defensible instead of hopeful.