The Two Main Methods

Most self-employed taxpayers calculate deductible car expenses using one of two methods: the standard mileage rate method or the actual expense method. If the taxpayer qualifies to use both, it is often worth comparing them. The IRS provides detailed guidance in Publication 463.

At The Reed Corporation, we often explain that there are really three core issues in this area: what counts as business driving, whether the taxpayer should use the standard mileage rate or actual expenses, and how depreciation works if the actual-expense method is used.

Standard Mileage Rate

For 2025, the IRS standard mileage rate for business use is 70 cents per mile. This rate is intended to represent the operating cost of a vehicle used for business.

Under this method, the taxpayer generally multiplies business miles by the standard mileage rate and then adds certain separately deductible items if applicable, such as business parking and tolls.

Why People Like This Method

The mileage method is often simpler and easier to administer. It avoids many of the complexities of tracking actual operating costs and depreciation calculations.

But It Still Requires Records

The mileage method is not the same as estimating whatever sounds reasonable. The taxpayer still needs a mileage log or equivalent substantiation showing:

• Total business miles
• Total miles driven during the year
• Dates of travel
• Destinations
• Business purpose

Actual Expense Method

Under the actual expense method, the taxpayer deducts the business-use percentage of actual operating costs for the vehicle. These can include:

• Gas and oil
• Repairs and tires
• Insurance
• Registration
• Lease payments
• Garage rent
• Depreciation (if the vehicle is owned)

This method can produce a larger deduction in some cases, especially where the vehicle is expensive to operate or where business-use percentage is high.

Business Miles vs. Commuting

One of the most important distinctions in this area is that commuting is generally not deductible. Driving from home to a regular work location is usually considered personal commuting, not business mileage.

But driving from one business location to another, or from the principal place of business to a client site, can be deductible business use.

For Schedule C taxpayers with a qualifying home office, this can matter a lot. If the home office qualifies as the principal place of business, trips from the home office to other business locations may be treated differently than ordinary commuting.

Depreciation

If the taxpayer uses the actual expense method and owns the vehicle, depreciation is often part of the deduction. Depreciation reflects the tax-system idea that the cost of a business asset should generally be recovered over time rather than deducted all at once.

Vehicle depreciation can be affected by:

• Luxury auto limits
• Section 179 expensing
• Bonus depreciation rules
• Business-use percentage

The details can become technical quickly, which is one reason many taxpayers prefer the mileage method. See IRS Publication 946 for depreciation details.

Why the First-Year Choice Matters

In some cases, the first-year choice between mileage and actual expenses matters later. Depending on how the vehicle is first used and what depreciation methods were claimed, the taxpayer’s flexibility to switch methods later may be affected.

This is one of the reasons vehicle deductions should not be treated casually. A rushed decision in the first year can shape future tax treatment.

Leased Vehicles

Leased vehicles have their own rules. Taxpayers using the actual-expense method generally deduct the business-use percentage of lease payments, subject to certain adjustments. Taxpayers using the mileage method still use mileage-based deduction treatment if they qualify.

Mixed-Use Vehicles

Most taxpayers use the same car for both business and personal reasons. That is normal, but it makes recordkeeping essential. The deduction is generally limited to the business-use percentage, not total use.

Common Mistakes

The most common mistakes include:

• Deducting commuting as business mileage
• Failing to keep a mileage log
• Deducting 100% of the vehicle when use is mixed
• Ignoring depreciation rules under the actual-expense method
• Confusing car payments with deductible expenses — a car payment itself is not simply deducted like rent; under actual-expense rules, the economics are split between depreciation, interest in some cases, and other related cost treatment

Which Method Is Better?

There is no universal answer. The mileage method is often cleaner and easier. The actual-expense method may be more favorable where vehicle costs are high or business use is significant. The right choice depends on the taxpayer’s facts, records, and long-term vehicle plan.

Why This Deduction Matters

For many Schedule C taxpayers, vehicle costs are one of the most meaningful recurring business expenses. But because the deduction is so common, it is also an area where sloppy reporting creates risk. A well-supported deduction can be powerful. A guessed-at deduction is dangerous.

For related topics, see our guides on the home office deduction, estimated tax payments for freelancers, and how Form 1040 tax returns work overall.