IRS Mileage Deduction Calculator

Taxpayers who use a vehicle for business have two options: the standard mileage rate or the actual expense method. Under the actual expense method, you track every vehicle-related cost -- gas, oil changes, tires, insurance, registration, lease payments or depreciation, and repairs -- then multiply the total by your business-use percentage. A vehicle driven 15,000 miles total with 10,000 business miles has a 66.7% business-use rate.

The standard mileage method is simpler and often produces a larger deduction for drivers with moderate annual mileage (under 20,000 business miles) and fuel-efficient vehicles. The actual expense method typically wins for expensive vehicles with high insurance and depreciation costs, or older vehicles with significant repair expenses. For example, a delivery driver putting 30,000 business miles on a vehicle with $12,000 in annual expenses gets $21,750 from the standard rate but only $12,000 from actual expenses.

A critical restriction: you must elect the standard mileage rate in the first year the vehicle is used for business. If you use actual expenses in year one, you are locked into that method for the life of the vehicle. Also, the standard mileage rate cannot be used if you have claimed Section 179 or bonus depreciation on the vehicle, or if you operate a fleet of 5 or more vehicles simultaneously.

The IRS requires contemporaneous written records to substantiate mileage deductions under IRC Section 274(d). Each trip log entry must include: the date of the trip, the destination (name and address), the business purpose, and the miles driven. You must also record the vehicle's odometer reading at the beginning and end of each tax year. Without proper documentation, the IRS can disallow the entire mileage deduction during an audit.

Commuting miles -- travel from home to a regular workplace -- are never deductible. However, travel from one business location to another, travel to meet clients, and travel from a home office (that qualifies as a principal place of business) to any other business location are all deductible. A taxpayer with a qualifying home office can deduct all business travel from the moment they leave home.

The IRS accepts digital mileage tracking apps as valid records, provided the data includes all required elements. Many audits are triggered by mileage deductions that appear disproportionate to income or industry norms. Self-employed individuals who claim more than 20,000 business miles annually should be prepared to substantiate each trip with detailed records.