Gas Trip Cost Calculator
Plug in your distance, your vehicle's fuel efficiency, and the price of gas to estimate what a road trip will actually cost, then split it fairly across everyone riding along.
Last updated
Defaulted to a reasonable national average, edit it to match your local price.
How to estimate road trip gas costs
The math behind a road trip gas estimate is simple once you have the three key numbers: how far you're driving, how efficiently your vehicle uses fuel, and what gas costs where you'll be buying it. Divide your total distance by your vehicle's MPG to get the gallons you'll burn, then multiply that by the price per gallon to get your total cost. For kilometers and liters, the formula flips slightly: multiply distance by your car's liters-per-100km rating, divide by 100, then multiply by the price per liter. Round trips simply double the distance before you run the math. None of this accounts for tolls, food, or lodging, it's purely the fuel, but it's usually the single biggest variable cost on a road trip, so getting a solid number upfront makes budgeting the rest of the trip much easier.
MPG and fuel-cost math here follows standard EPA fuel economy reporting conventions, check fueleconomy.gov for your specific vehicle's rating.
Tips to save on gas for long trips
- Use cruise control on the highway, it smooths out acceleration and can meaningfully improve fuel economy.
- Check your tire pressure before you leave, underinflated tires increase rolling resistance and burn more gas.
- Plan your route to avoid unnecessary detours and heavy traffic corridors when a similar-length alternate exists.
- Clear out excess weight from the trunk, extra cargo makes your engine work harder over long distances.
- Use a gas price app to find the cheapest stations along your route instead of filling up wherever is convenient.
- Avoid unnecessary idling at rest stops, and pack your own snacks and drinks to cut down on extra stops.
Frequently asked questions
How accurate is this estimate?
It's a solid ballpark based on distance, your vehicle's average fuel efficiency, and the gas price you enter. Real trips vary with driving style, load, and road conditions, so treat the number as a planning estimate rather than an exact total.
Does this account for traffic or elevation?
No. Traffic, hills, and highway versus city driving all affect real-world fuel economy, sometimes significantly. If your route has a lot of mountains or stop-and-go traffic, consider lowering your MPG input a bit to get a more realistic estimate.
How do I find my car's MPG?
Check your owner's manual or the window sticker for the EPA-estimated combined MPG, or look up your exact make, model, and year on fueleconomy.gov. You can also calculate your own average by dividing miles driven by gallons used over a few fill-ups.