Fuel cost math.

In plain English

Fuel cost math is the basic way to figure out what driving costs you in fuel. For a gas car, you divide the miles you drive by the car's miles per gallon (MPG) to get gallons used, then multiply by the price per gallon. For an electric car, you do the same idea with kilowatt-hours and your electricity rate instead. The point is to compare cars and trips on an even footing, often as cost per mile, so a higher sticker price with better efficiency can still be cheaper to drive. Fuel prices and electricity rates change over time and by region, so the math is only as current as the prices you plug in.

01Why it matters

Fuel is one of the largest ongoing costs of owning a car, and a small difference in MPG or fuel price adds up to hundreds or thousands of dollars over the years you keep the car.

02The math, step by step

Say you drive 12,000 miles a year in a car that gets 25 MPG. That is 480 gallons a year. Multiply by your local gas price to get the yearly fuel cost. As of the week of June 8, 2026, the U.S. average regular gasoline price was about $4.15 per gallon, per the EIA, so 480 gallons works out to roughly $1,990 a year at that price. A car that gets 40 MPG over the same 12,000 miles uses only 300 gallons, so it costs less to drive even before you compare anything else. Use your own local price for a closer estimate.

03What this is NOT

04Receipts

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