Trip Fuel Calculator
Estimate fuel, cost and trip distance with round-trip and extra-distance options
Estimated fuel cost
How we calculated it
About the Trip Fuel Calculator
Trip Fuel Calculator estimates the amount of fuel required for a journey from distance and vehicle fuel economy. It focuses on fuel quantity rather than the full monetary trip budget.
The estimate improves when you use recent real-world economy instead of an optimistic rated figure, especially for routes with traffic, hills or heavy loads.
How to Use the Trip Fuel Calculator
- Enter total trip distance, including the return leg if appropriate.
- Enter the vehicle’s expected fuel economy.
- Choose compatible economy and distance units.
- Calculate the fuel quantity and add a reserve if the route has limited refuelling options.
How the Calculation Works
For MPG-based economy, fuel required = distance ÷ MPG. For L/100 km, fuel required = distance(km) × consumption ÷ 100.
The calculator converts units first when distance and economy are expressed in different supported systems.
Worked example
Trip Fuel Calculator Worked Example
420 miles at 28 MPG
Fuel required = 420÷28 = 15 gallons. If planning a 10% operational reserve, that would be 16.5 gallons of planning capacity, though actual tank and refuelling strategy remain separate.
Result guide
Understanding Your Trip Fuel Calculator Result
The result is a fuel-quantity estimate. Actual use can rise with idling, detours, speed, weather, towing or terrain.
Before you rely on the answer
Assumptions and Limitations
- Fuel economy is representative of the trip.
- Distance reflects the intended route.
- Idling and detours are included only insofar as they are reflected in the economy or distance assumption.
Practical tip
Using This Result in Practice
For remote travel, separate calculated fuel use from reserve fuel. A reserve is a planning decision and should not be hidden inside an artificially low MPG assumption.
Related calculations
Useful Calculations to Continue With
If you also want the money required for the trip, use the Fuel Cost Calculator after estimating fuel quantity.
If your vehicle economy and route use different unit systems, convert the economy first with the Fuel Economy Converter.
Common questions
Trip Fuel Calculator FAQ
How do I calculate gallons needed for a trip?
Divide trip miles by miles per gallon.
How do I calculate litres needed from L/100 km?
Multiply distance in kilometres by L/100 km and divide by 100.
Why might actual trip fuel be higher?
Traffic, idling, hills, high speed, weather, load and detours can reduce real-world economy.