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Calculator

Break-even calculator

The cheaper car up front is not always the cheaper car overall. This calculator finds the mileage where that flips.

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Cumulative cost of ownership in dollars, against miles driven. Each line starts at the purchase price and rises by that car's running cost per mile.

Fuel and electricity defaults above come from the EIA gasoline price series ($4.085/gal) and the EIA electricity price series ($0.1834/kWh), checked 2026-08-27. Edit either field for your own market.

What this calculates

Pick two vehicles and this tool compares total cost as a function of miles driven: purchase price plus miles times cost per mile, for each car. If one car is both cheaper to buy and cheaper to run, there is no break-even — it simply wins at every mileage, and the calculator says so directly instead of returning a meaningless number. Otherwise, one car costs less up front while the other costs less per mile, and the two total-cost lines cross at some point. That crossing mileage is the break-even: drive fewer miles than that over the ownership period and the cheaper upfront car wins; drive more and the cheaper-to-run car wins. The chart plots both cars' cumulative cost from zero miles out to a horizon comfortably past the break-even point, so the crossing is visible rather than just stated as a number.

Assumptions baked in

Cost per mile for each car is the same energy-plus-maintenance-plus-depreciation figure used by the cost-per-mile calculator, computed automatically from the selected vehicle's data and the fuel or electricity price entered here — it is not a separate, hand-typed estimate. Purchase price defaults to each vehicle's typical used-market high price and is meant to be edited to whatever price is actually on offer, since the difference between two real listings is what actually matters, not two catalog averages. The comparison assumes constant per-mile cost for the full ownership period; it does not model a car needing a major repair at year eight or fuel prices changing over the years being compared, which real ownership always includes to some degree. It also assumes annual mileage stays the same for both cars, so it is most accurate when comparing two vehicles under one driver's expected usage pattern rather than two hypothetical drivers with different habits.

Full formulas and how each vehicle's per-mile cost is derived are on the methodology page.