Fuel Cost Calculator

How it works

The calculator divides the distance you will drive by your vehicle's fuel economy to get the gallons the trip burns, then multiplies by the price per gallon to get the cost. Choosing round trip doubles the distance.

Cost per mile is the fuel cost spread over the distance. It depends only on fuel price and MPG, so it is a quick way to compare two vehicles or two fuel prices without picking a trip.

Use the EPA combined figure for your vehicle, or better, the MPG your own car actually gets. Highway driving usually beats the combined figure; towing, city driving and cold weather fall short of it.

Formula

total distance = distance × 2        for a round trip
gallons used   = total distance ÷ MPG
fuel cost      = gallons used × price per gallon
cost per mile  = fuel cost ÷ total distance

Example

A 300-mile drive in a car that gets 30 mpg, with gas at $3.50 a gallon, uses 10 gallons and costs $35.00 in fuel, or $0.117 per mile.

The same trip as a round trip is 600 miles: 20 gallons and $70.00. The cost per mile is unchanged at $0.117.

Assumptions and limitations

• Fuel economy is treated as constant for the whole trip. Real mileage varies with speed, load, terrain, weather and traffic.
• Fuel price is treated as constant. Prices along a long route differ.
• Only fuel is counted. Tolls, parking, maintenance, tire wear and depreciation are not included.
• A round trip assumes the return leg is the same distance as the outbound leg.

Frequently asked questions