Fuel Cost Calculator
Commutes, road trips and errands have a price at the pump. See it clearly, per trip and per month.
Last updated: August 5, 2026
How to figure driving costs
The fuel needed for any trip is the distance divided by fuel economy. Multiply that by the price per gallon and you have the per-trip cost. Multiply by trips in the week for the recurring figure — the number most people underestimate by a wide margin, since $4 a trip disappears silently.
The formulas
Worked example
30 miles each way five days a week (10 trips), 28 mpg, $3.50/gal.
Gallons = 1.07/trip. Cost = $3.75/trip. Weekly = $37.50, monthly ≈ $162.
Switch to a 40 mpg car and the monthly number falls to about $113 — a $50 monthly difference that quietly buys a car payment of its own.
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Frequently asked questions
What if I drive mostly highway vs city?
Fuel economy varies with the driving. If your commute is mostly highway, use the highway figure; for stop-and-go trips use the city figure. The calculator just uses the number you enter.
How do I get the monthly figure for a two-car household?
Run the calculator once per car and add the results, since economy and trips differ. The total is the number to feed a household budget.
Do electric vehicles fit here?
Use this with kWh per 100 miles and cost per kWh to get an analogous figure, but for accuracy with an EV, many owners compare cost per mile — which this tool supports by entering $/mile and 1 mpg.
This is fuel cost only, using the values you enter. Real fuel economy varies with driving and terrain; there may be other vehicle costs beyond fuel.