Mileage Deduction Calculator

Turning business miles into a deduction

If you drive for work, those miles are money. The IRS lets self-employed people deduct business driving using the standard mileage rate — a single per-mile figure that bundles together gas, maintenance, insurance, and depreciation. For 2026 the rate is $0.725 per mile (IRS Notice 2026-10, published December 29, 2025). Multiply your business miles by that rate and you have your deduction; this tool then shows what it's actually worth in tax.

Because a sole proprietor's profit is taxed by both income tax and the 15.3% self-employment tax, a mileage deduction reduces both. That's why the tool values your deduction at a combined marginal rate — your income-tax bracket plus the SE-tax marginal (15.3% × 92.35%) — rather than income tax alone.

Standard rate vs. actual expenses

You have two ways to deduct vehicle costs, and you pick one per vehicle:

• Standard mileage rate — the simple route. Track your miles, multiply by the rate. That's it. It's usually the better choice for higher-mileage, lower-cost vehicles.
• Actual expenses — deduct your real vehicle costs (gas, repairs, insurance, lease or depreciation) times your business-use percentage. This can win for expensive vehicles driven modestly.

One catch worth knowing: if you want the flexibility to switch methods in later years, you generally must use the standard mileage rate in the *first* year you put the car into business use. If you're weighing the two, the Write-Off Estimator's vehicle line covers the actual-expense side.

Which miles count

Deductible business miles include driving between work locations, to clients or job sites, and for business errands. Your regular commute — home to a main workplace — is not deductible. If you have a qualifying home office, though, trips from there to other business locations do count, which is one quiet advantage of the home-office setup.

Records make or break the deduction

Mileage is a commonly audited deduction, and the fix is simple: keep a contemporaneous log. Record the date, miles, and business purpose of each trip, plus your total annual mileage. Apps that track trips by GPS satisfy this easily. A number you reconstruct from memory months later is exactly what auditors disallow — so log as you go.

How to use the result

• Deduction is what comes off your taxable profit.
• Tax saved is the real cash benefit at your combined marginal rate.
• Use it to decide between methods, and to remember that mileage is genuine money you're leaving on the table if you don't track it.

What this assumes

The standard-mileage method (not actual expenses), a valid mileage log, and a sole proprietor filing on Schedule C. You can't claim both standard mileage and actual vehicle expenses for the same miles.

Estimates only, not tax advice. Confirm your method and recordkeeping with a qualified professional.