Transparent method
The formula
Worked example
Example inputs
How to interpret the result
The deduction rides on the current official per-mile rate, which changes periodically, and using a stale rate from a prior year either overstates or understates the real deduction depending on which direction the rate moved. A small per-mile gap compounds fast across a year of business driving.
Before you rely on it
What to check
Confirm the mileage rate entered matches the current official rate for the tax year being calculated, not a rate remembered from a previous year.
The common error
Where people go wrong with business mileage deduction calculator
Reusing last year's mileage rate out of habit. The rate changes periodically, and a stale rate applied across thousands of annual business miles produces a deduction that's measurably off from what's actually allowed.
Sensitivity evidence
How mileage rate per mile changes the potential mileage deduction
| Mileage rate per mile | Potential mileage deduction | Estimated tax savings |
|---|---|---|
| $0.56 | $6,720 | $2,016 |
| $0.63 | $7,560 | $2,268 |
| $0.70worked example | $8,400 | $2,520 |
| $0.77 | $9,240 | $2,772 |
| $0.84 | $10,080 | $3,024 |
Every input, tested
Which input moves the potential mileage deduction most
| Input | Tested from | To | Potential mileage deduction at each end | Swing |
|---|---|---|---|---|
| Business miles | 10,800 | 13,200 | $7,560 to $9,240 | $1,680 (20%) |
| Mileage rate per mile | $0.63 | $0.77 | $7,560 to $9,240 | $1,680 (20%) |
| Marginal tax rate | 28.0% | 32.0% | $8,400 to $8,400 | none |
Two variables at once
Potential mileage deduction by mileage rate per mile and business miles
| Mileage rate per mile \ Business miles | 9,600 | 12,000 | 14,400 |
|---|---|---|---|
| $0.56 | $5,376 | $6,720 | $8,064 |
| $0.63 | $6,048 | $7,560 | $9,072 |
| $0.70 | $6,720 | $8,400 | $10,080 |
| $0.77 | $7,392 | $9,240 | $11,088 |
| $0.84 | $8,064 | $10,080 | $12,096 |
Step by step
The worked example, input by input
| Input | Value used |
|---|---|
| Business miles | 12,000 |
| Mileage rate per mile | $0.70 |
| Marginal tax rate | 30.0% |
| Potential mileage deduction | $8,400 |
| Estimated tax savings | $2,520 |
Where the inputs come from
Business miles are the miles driven for business purposes, from a mileage log that records date, destination, purpose and miles, and the rate per mile is the IRS standard mileage rate for the year, 70 cents for 2025 and updated each year. Marginal tax rate estimates the savings. Commuting from home to your regular workplace is not deductible business mileage, but trips between job sites or to clients generally are, and a home office can change the starting point.
When the result stops applying
Records are essential: the IRS can disallow deductions without a contemporaneous log. Employees generally cannot deduct mileage on their own returns. If you use the standard rate in the first year, you can switch to actual expenses later in some cases, but the reverse is limited. State rules and other rates, such as for medical or charitable driving, differ.
What to compare it with
Compare with the fuel cost and vehicle total cost of ownership calculators to see your real costs, and see the home office and self-employment tax pages for related deductions. The quarterly tax calculator helps plan payments on the reduced income. Use a mileage app to keep logs.
People also ask
Frequently asked questions
What is the standard mileage rate?
A per-mile amount set by the IRS each year that covers the costs of operating a vehicle for business, 70 cents a mile for 2025.
Is my commute deductible?
No. Driving between home and your regular place of work is personal commuting, but trips from a home office to clients or between work sites are generally deductible.
Do I need a mileage log?
Yes. Keep a record of the date, purpose, destination and miles for every business trip, since the IRS requires adequate records.