How the road trip gas calculator works
Enter where you're starting and where you're going, choose your vehicle, and tell us how much fuel you have. We map the driving route, work out how many miles you'll drive in each state, and multiply those miles by the weekly average fuel price for that area. The result is an estimate of your fuel cost for the whole trip and for each leg.
We also plan your fuel stops. We work out how far you can go on the fuel you have, keep a reserve in the tank (25% unless you choose otherwise), and suggest stations near each point where you'll want to fill up, showing only the ones we're most confident about unless there are none nearby.
For RVs, we route around known low bridges and propane-restricted tunnels where our data covers them, and every RV plan reminds you to use an RV GPS for your final route.
Weekly regional prices from the U.S. Energy Information Administration
Fuel prices come from the U.S. Energy Information Administration (EIA) weekly retail price survey. EIA collects prices from a sample of about 1,000 gasoline stations (and about 590 diesel outlets) every Monday at 8 a.m. local time and publishes the averages on Tuesday morning. Averages are published for the nation, for regions of the country (such as the Midwest or the Gulf Coast), and for a handful of individual states.
For each state on your route, we use EIA's average for that state where EIA publishes one, or for its region otherwise. The per-gallon prices are shown exactly as EIA published them. The trip cost is our own calculation from those prices, so we label it as an estimate. Prices at individual stations can be noticeably higher or lower, especially on interstates and in tourist areas.
Senior Traveling Guide is independent and is not affiliated with or endorsed by the U.S. Energy Information Administration, Mapbox, or any fuel station or brand shown. Station names and brands are shown for information only.
Seven ways to cut your fuel cost on a road trip
- Slow down: According to fueleconomy.gov, each 5 mph you drive over 50 mph is like paying an additional $0.21 per gallon, and slowing down by 5 to 10 mph can save about 7% to 14%.
- Drive smoothly: Speeding, rapid acceleration, and hard braking can lower mileage by roughly 15% to 30% at highway speeds, according to fueleconomy.gov.
- Check your tires: Under-inflated tires can lower gas mileage by about 0.2% for every 1 psi drop. Check them cold, before you set out.
- Travel light: An extra 100 pounds can cut mileage by about 1%, and a roof cargo box can cost far more at highway speeds.
- Go easy on the A/C in extreme heat: In very hot weather, air conditioning can reduce a conventional car's fuel economy by more than 25%, especially on short trips.
- Don't idle: Idling can use a quarter to half a gallon an hour, depending on the engine and A/C use.
- Fill up before the interstate: Stations a short drive off the highway are often cheaper than those right at the exit, and filling up before your tank gets low gives you time to choose.
RV gas mileage: what to expect
RVs vary widely, and most aren't rated by the EPA, so it pays to use your own figure if you know it. As a rough guide from RV dealer and rental company figures:
- Class A motorhome: about 6 to 10 MPG
- Class C motorhome: about 10 to 15 MPG
- Class B camper van: about 18 to 22 MPG, sometimes more
- Towing a travel trailer: expect your truck's mileage to drop by roughly a third to a half; tall, boxy trailers are at the high end
Our RV presets show a typical figure with a note when it's owner-reported rather than EPA-rated. Change it to your own number for a better estimate. For RV-specific planning, try our propane calculator, tongue weight calculator, and generator size calculator.
Find gas stations along your route
Knowing what a trip will cost in fuel is half the job. Knowing where to fill up is the other half, especially in a motorhome or on long, empty stretches of highway. When you plan a trip, the calculator works out how far you can go on the fuel you have and suggests gas stations along your route, near each point where you'll want to fill up.
- Stops where you need them: each suggested stop sits near the point where your tank reaches the reserve you chose, so you aren't hunting for a station with the needle on empty.
- Stations we're confident about: at each stop we show only the stations we're most confident about. If there are none nearby, we show the less certain ones and say so.
- For RVs: RV plans add route safety notes, such as low bridges and propane-restricted tunnels where our data covers them. Our station listings are still growing, so each plan tells you exactly which stations are covered on your route. Always use an RV GPS for your final route.
- On remote roads: out West and in the mountains, stations can be far apart and close early. Fill up when you have the chance rather than pushing on to the next town.
Budgeting the whole trip? Fuel is only one part of a road trip's cost. Use the fuel estimate as your starting point, then add lodging, meals, and park or attraction fees. Our road trip guides for seniors suggest relaxed daily distances and where to stay along the way.
What we keep, and what we don't
We don't ask you to sign up, and we don't store the places you enter or your route. Address suggestions and maps are provided by Mapbox. Your trip details are sent to our planning service only to work out your route and cost.