Fuel Cost Calculator – Estimate Trip Cost from Distance and Efficiency
Free fuel cost calculator: enter distance, fuel efficiency (mpg or L/100km) and price per unit to get total fuel cost. Plan road trips and compare vehicle costs. No sign-up, runs in your browser.
Fuel Cost Calculator
Enter distance, fuel efficiency and price per unit to estimate total fuel cost for your trip.
How the fuel cost calculator works
The calculator uses distance, fuel efficiency and price per unit:
fuel_used = distance ÷ mpg (or (distance ÷ 100) × L/100km for metric)
total_cost = fuel_used × price_per_unit
For example, 300 miles at 30 mpg with $3.50/gal uses 10 gallons and costs $35. The tool supports both US (mpg, gallons) and metric (L/100km, liters) units.
Planning trips and budgeting for fuel
Knowing how much a trip will cost in fuel helps you budget, compare vehicles, and decide when to fill up. Fuel prices change often, and efficiency varies by driving conditions, so the result is an estimate. Use your vehicle's stated mpg or L/100km from the manual or fuel economy label; for a more accurate figure, track several tanks and compute your actual efficiency with our fuel efficiency calculator.
Highway driving typically uses less fuel per mile than city driving. If your trip mixes both, use a weighted average or run separate calculations. Towing, roof racks, and heavy loads reduce efficiency. Cold weather can also increase consumption. When in doubt, add a buffer of 10–15% to your estimate.
For road trips across regions with different fuel prices, you can run multiple calculations and sum the costs. Some drivers use apps to find the cheapest stations; this calculator gives you the baseline cost so you can see how much you might save by filling up in a cheaper area.
When comparing cars, fuel cost is one factor alongside purchase price, insurance, and maintenance. A more efficient vehicle may cost more upfront but save money over time. Use this calculator to project annual fuel costs for your typical mileage and compare different vehicles. For loan payments on a new car, pair this with our car loan calculator.