Enter your trip distance, your vehicle’s fuel economy, and the price per gallon to see how much gas the trip will actually cost.
Distance (miles):
Fuel economy (MPG):
Price per gallon ($):
How It Works
The calculator divides trip distance by your vehicle’s MPG to find gallons needed, then multiplies by the price per gallon for total cost, and divides cost by distance for a per-mile figure.
How to Use This Tool
- Enter the trip distance in miles.
- Enter your vehicle’s fuel economy in miles per gallon.
- Enter the current price per gallon and click Calculate.
Real-world fuel economy varies with speed, terrain, load, and driving style, so treat the result as an estimate rather than an exact figure.
The Formulas
- Gallons needed = distance ÷ MPG
- Total fuel cost = gallons needed × price per gallon
- Cost per mile = total fuel cost ÷ distance (or price per gallon ÷ MPG)
Worked example: a 300-mile trip in a car that gets 30 MPG needs 300 ÷ 30 = 10 gallons. At 3.50 a gallon, the fuel costs 35, which works out to about 11.7 cents per mile. For a round trip, double the distance: 600 miles needs 20 gallons and costs 70.
How to Get a More Accurate Number
The MPG printed on a window sticker is a lab estimate. Your real number depends on how and where you drive. To find yours, fill the tank, reset the trip meter, drive normally, then fill up again and divide the miles driven by the gallons you added. Use that figure for planning. A few things that commonly lower fuel economy:
- High speed: Fuel use rises quickly above typical highway speeds.
- Extra weight and roof cargo: Heavier loads and roof boxes increase drag and fuel use.
- Low tire pressure: Underinflated tires make the engine work harder.
- Hills, heat, and stop-and-go traffic: Terrain and air conditioning both raise consumption.
If your car shows fuel economy in liters per 100 kilometers, divide 235.2 by that number to convert to MPG. For example, 7.8 L/100 km is about 30 MPG.
Did You Know?
- Highway driving at a steady speed typically gets better MPG than stop-and-go city driving.
- Cost per mile is a handy figure for comparing a road trip’s fuel cost against a flight or other travel option.
Frequently Asked Questions
Does this account for tolls or other trip costs?
No, this only estimates fuel cost. Tolls, parking, and food would need to be added separately for a full trip budget.
What if my trip is round trip?
Enter the full round-trip distance (there and back) to get the total cost for the whole trip.
How do I split fuel costs between passengers?
Take the total fuel cost from the calculator and divide it by the number of people in the car, including the driver if you want an even split. Many groups also agree to share tolls and parking the same way.
Is it cheaper to drive or fly?
Use the cost per mile as a starting point. Multiply it by the round-trip distance, add tolls and parking, and compare that with the flight price plus transport at each end. Driving usually looks better when several people share one car, and flying when the distance is long.
Does this work for electric vehicles?
Not directly, since electric cars are rated in kilowatt-hours rather than gallons. You can get a rough comparison by converting your car’s efficiency into an equivalent cost per mile using your electricity price.