Fuel Cost Calculator
Calculate the fuel cost for any trip based on distance, fuel efficiency, and gas price.
The Formula
Annual cost = Cost per mile × Annual miles
Cost per mile = Fuel Price / MPG
Gallons = 250 / 32 = 7.81
Cost = 7.81 × $3.45
= $26.95 for the trip
How to Calculate Trip Fuel Cost
The formula is straightforward: divide your trip distance by your vehicle's fuel economy (MPG) to get gallons needed, then multiply by the price per gallon. A 400-mile road trip in a car that gets 28 MPG at $3.40 per gallon: 400 / 28 = 14.3 gallons needed, times $3.40 = $48.57. This calculator handles both imperial (miles and gallons) and metric (kilometers and liters) inputs, and lets you compare multiple vehicles side by side to see how much you save in a more fuel-efficient car.
Real-World MPG vs. EPA Estimates
Your car's actual fuel economy on a given trip can differ significantly from the EPA-rated sticker MPG. Highway driving at a steady 65–70 mph typically matches or exceeds EPA highway ratings. City driving with frequent stops is less efficient. Driving at high speeds (above 75 mph) dramatically reduces fuel economy — aerodynamic drag increases with the square of speed. Cold weather reduces efficiency by 10–20% for conventional vehicles (more for EVs). Cargo weight, tire pressure, and air conditioning all affect real-world MPG as well.
Comparing Fuel Costs Across Vehicles
The difference between 25 MPG and 35 MPG is more impactful than most people realize. At $3.50/gallon, driving 15,000 miles per year in a 25 MPG car costs $2,100 in fuel. The same driving in a 35 MPG car costs $1,500 — a savings of $600 per year. Over 5 years that is $3,000. This calculator makes those comparisons easy, which is useful when deciding between vehicles or evaluating whether a hybrid premium is worth it for your driving habits.
Frequently Asked Questions
How can I improve my car's fuel economy?
The most impactful changes: slow down (every 5 mph above 60 reduces fuel economy by about 7%), keep tires properly inflated (under-inflation reduces MPG by 0.2% per PSI), remove unnecessary weight from the trunk, use cruise control on highways to maintain steady speed, and avoid aggressive acceleration and hard braking. Regular maintenance (clean air filter, fresh spark plugs, correct motor oil) also helps. AC uses significant fuel at low speeds but is more efficient than open windows at highway speeds.
What is a good MPG for a car?
For modern gasoline-powered vehicles, 30+ MPG combined is considered good, and 35+ is excellent. Compact cars typically achieve 32–40 MPG. Mid-size sedans average 28–35 MPG. SUVs and trucks range from 18–28 MPG. Hybrids typically achieve 45–55 MPG. EVs are rated in MPGe (miles per gallon equivalent) — most range from 90–130 MPGe, making them roughly 3–4x more energy-efficient than comparable gasoline cars.
How much does it cost to drive per mile?
At $3.50 per gallon and 28 MPG, the fuel cost is $3.50 / 28 = $0.125 per mile, or 12.5 cents per mile. The IRS standard mileage rate (used for tax deductions) also includes depreciation, maintenance, and insurance. For 2024, the IRS rate was 67 cents per mile — fuel is roughly one-fifth of the total cost of driving.
How do I calculate fuel cost for a trip with multiple stops?
Sum the distances of each leg of the trip to get total mileage, then apply the standard formula: total miles / MPG x price per gallon. If the driving conditions vary significantly between legs (heavy city driving vs. highway), you may want to calculate each segment separately using the appropriate MPG estimate for that driving type and add the results.
Does using premium gas improve fuel economy?
For most cars, no. Premium gasoline is only necessary or beneficial in engines designed or required to use it (typically high-performance or turbocharged engines). In a car that recommends regular fuel, using premium provides no measurable efficiency benefit. Always use the octane rating specified in your owner's manual — the minimum required, not premium as a default.