An RV fuel cost calculator estimates how much you will spend on gas or diesel for any motorhome, campervan, or towing trip. Select your RV type to auto-fill typical MPG, enter your trip distance and fuel price, and get an instant breakdown of gallons needed, total cost, cost per mile, and estimated fill-ups.
RV & Trip Details
Typical range: 6–10 MPG
Per-Leg Breakdown
| Leg | Distance (mi) | Gallons | Cost |
|---|---|---|---|
| Total |
Typical RV Fuel Economy Reference
| RV Type | MPG Range | Typical MPG | Typical Tank |
|---|---|---|---|
| Class A Motorhome (Gas) | 6–10 | 8 | 80–150 gal |
| Class A Motorhome (Diesel) | 8–14 | 10 | 100–150 gal |
| Class C Motorhome | 10–16 | 13 | 25–55 gal |
| Class B Van / Campervan | 15–22 | 18 | 20–30 gal |
| Truck Towing Travel Trailer | 8–14 | 10 | 26–36 gal |
| Truck Towing 5th Wheel | 7–12 | 9 | 26–36 gal |
| SUV Towing Small Trailer | 12–18 | 14 | 18–26 gal |
MPG varies significantly based on terrain, speed, wind, weight, and driving habits. Track your actual fill-ups for the most accurate estimates.
How to Use the RV Fuel Cost Calculator
Planning an RV trip means budgeting for fuel, and motorhomes burn a lot more gas than passenger cars. This RV fuel cost calculator gives you an accurate estimate of how much you will spend on fuel so you can budget for campground fees, food, and attractions without fuel costs being a surprise.
Step 1: Select Your RV Type
Choose your RV type from the preset dropdown. Each preset auto-fills a typical MPG value for that class: Class A gas motorhomes average about 8 MPG, Class A diesel about 10 MPG, Class C motorhomes about 13 MPG, and Class B campervans about 18 MPG. Towing setups are included too, from trucks pulling travel trailers to SUVs with small trailers. If you know your exact MPG, select "Custom" and enter it manually.
Step 2: Enter Trip Distance and Fuel Price
Enter your one-way trip distance in miles. Use Google Maps or your GPS to get the driving distance. Then set the fuel price per gallon. The calculator defaults to approximate US averages ($3.50 for gas, $3.80 for diesel), but you should adjust this to match prices along your route. Diesel RVs should select the diesel fuel type, which updates the default price accordingly.
Step 3: Add Optional Details
Enable the round trip toggle if you are returning the same way. Enter your tank size to see how many fill-ups you will need along the route. For multi-destination trips, increase the number of legs and customize each leg distance to see a per-leg cost breakdown. This is especially useful for RV trips that visit multiple parks or campgrounds.
Step 4: Read the Results
The calculator shows four key numbers: total fuel cost, total gallons needed, cost per mile, and estimated fill-ups. The cost per mile figure is particularly useful for RV owners because it lets you quickly estimate the fuel cost of any side trip or detour. For example, if your cost per mile is $0.44, a 50-mile detour to a national park costs about $22 in fuel. The per-leg breakdown table helps you plan fuel stops around gas stations with the best prices.
Tips for Reducing RV Fuel Costs
Drive at 55–60 mph instead of 65+ to improve MPG by 15–20%. Keep tires properly inflated, reduce rooftop cargo, and plan routes that avoid steep mountain passes when possible. Fueling up at truck stops along interstates is often cheaper than gas stations near campgrounds or tourist areas. Consider a fuel rewards credit card or apps like GasBuddy to find the cheapest fuel stops along your route.
Frequently Asked Questions
Is this RV fuel cost calculator really free?
Yes, completely free with no signup required. All calculations run locally in your browser. No trip data, distances, or fuel prices are stored or transmitted anywhere.
Is my data safe when using this tool?
Absolutely. Everything is calculated in your browser using JavaScript. No personal information, RV details, or trip plans are sent to any server. Your privacy is fully protected.
What MPG should I use for my motorhome?
Use the RV type presets as a starting point: Class A gas gets about 8 MPG, Class A diesel about 10 MPG, Class C about 13 MPG, and Class B campervans about 18 MPG. For the most accurate results, track your actual fill-ups over a few tanks.
How does towing affect fuel economy?
Towing a trailer typically reduces fuel economy by 25-40% compared to driving unloaded. A truck getting 20 MPG empty might get only 10-14 MPG towing. The heavier the trailer and the more aerodynamic drag, the worse the fuel economy.
What fuel price should I use for a long RV trip?
Use the average fuel price along your route, not just your local price. Gas and diesel prices can vary by $0.50 or more between states. Check GasBuddy or AAA's fuel price map for current prices along your planned route.
How do I calculate how many fuel stops I will need?
Enter your RV's tank size in the calculator. It divides total gallons needed by your tank capacity to estimate fill-ups. Most Class A motorhomes have 80-150 gallon tanks, Class C have 25-55 gallons, and Class B vans have 20-30 gallons.
Does the round trip toggle work with multi-leg trips?
Yes. When round trip is enabled, each leg distance is doubled to account for the return journey. The per-leg breakdown and total cost both reflect the round trip distances automatically.
What is the difference between gas and diesel RV fuel costs?
Diesel RVs typically get 20-30% better fuel economy than gas equivalents, but diesel fuel often costs $0.20-0.50 more per gallon. Over long trips, diesel motorhomes usually have lower total fuel costs despite the higher per-gallon price.