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The IRS gives you two ways. Only one is bigger.
Every business mile can be deducted two ways — the flat IRS rate or your share of what the car actually cost — and the gap is routinely thousands of dollars. This calculator runs both with your real numbers and shows the winner, plus the lock-in rule that decides which cars get to choose.
Rideshare drivers use it at tax time to confirm the standard rate really is the bigger deduction — and new gig drivers use it in year one because the lock-in rule makes that first-year choice permanent. It turns a shrug into a four-figure difference.
The IRS set a split year for 2026: 72.5¢/mile January through June and 76¢/mile July through December, a mid-year adjustment driven by fuel costs. A blended ~74¢ works for planning; for filing, track miles by half-year and apply each rate separately.
To preserve the right to switch methods, you must use standard mileage in the FIRST year the car is placed in business service. Choose actual expenses first and that car is locked into actual (with MACRS depreciation) for life. Leased cars that start on standard mileage must keep it for the entire lease.
Standard mileage, usually — a high-mpg car doing 20,000+ business miles often deducts 74¢/mi while actually costing 30–45¢/mi. Actual wins for expensive vehicles with low business mileage or big repair years. Either way you need a mileage log: apps, or a notebook with date, miles, and purpose.