Calculate exactly how much fuel you'll need and what it will cost for your next road trip.
Trip Details
Rough national estimate — update to your local price.
Total Fuel Cost
$0.00
Total Distance
0 mi
Gallons Used
0 gal
Cost does not include tolls or vehicle wear and tear.
Last updated: August 2026
Budgeting Your Next Road Trip
Whether you're planning a cross-country family vacation or just commuting to a new job, gas prices can take a major bite out of your budget. Knowing exactly how much a trip will cost allows you to split expenses fairly with friends or decide if driving is actually cheaper than flying.
How to Use This Tool
Enter the total distance of your trip, your vehicle's average MPG (miles per gallon), and the current price of gas. The tool instantly calculates the total amount of fuel you will use and the exact financial cost of the trip.
The Formula
(Distance ÷ MPG) × Price per Gallon = Total Fuel Cost
If you check "Round Trip," the distance is doubled before the calculation runs, since you'll need fuel for the return leg too.
Worked Example
Say you're driving 300 miles one-way in a car that gets 25 MPG, with gas at $4.10/gallon, and you're making it a round trip:
Total distance: 300 × 2 = 600 miles
Gallons needed: 600 ÷ 25 = 24 gallons
Total cost: 24 × $4.10 = $98.40
This estimate doesn't include tolls, parking, or wear-and-tear costs like tires and maintenance — for a longer trip you may want to budget an extra buffer for those.
Frequently Asked Questions
Most modern cars have a digital display on the dashboard that shows average MPG. Alternatively, you can look up your specific make and model on the EPA's Fuel Economy website.
Yes. Gas mileage usually peaks at speeds around 50 mph and decreases rapidly at speeds above 60 mph. Driving 75 mph instead of 65 mph can reduce fuel economy by up to 15%.
At low speeds (city driving), rolling the windows down is more fuel-efficient. At highway speeds, the aerodynamic drag from open windows uses more gas than running the AC.
Total distance (doubled if round trip) is divided by your vehicle's MPG to get gallons needed, then multiplied by your price per gallon: (Distance ÷ MPG) × Price per Gallon = Total Cost.
The default is a rough national average estimate and will not match your area. Gas prices vary significantly by state and even by station, so replace it with your local price — check a site like GasBuddy or AAA's fuel price tracker — for an accurate estimate.
No, it uses a single MPG figure you provide. If your trip is mostly highway, use your vehicle's highway MPG rating for a more accurate estimate; for mixed driving, use the combined MPG figure from your dashboard or the EPA rating.
Real-world MPG varies with driving speed, terrain, cargo weight, tire pressure, and traffic conditions. Treat this as a planning estimate rather than an exact figure, and check gas prices along your specific route since prices can shift at state lines.
Maintain a steady highway speed around 55-65 mph, keep tires properly inflated, remove excess roof cargo that adds drag, and use a gas price comparison app to find cheaper stations along your route.
