Fuel and journeys
Fuel cost calculator
Work out what a petrol or diesel journey costs in GBP, USD or EUR using Imperial or US MPG and fuel priced by the litre or US gallon.
Enter your journey details
Choose the currency and fuel-price basis that match your figures, then enter the price shown at the pump.
How the fuel cost calculation works
The calculator uses UK/Imperial MPG with a per-litre fuel price, or US MPG with a per-US-gallon price. It converts the journey into fuel volume, applies the pump price and projects repeated journeys across a typical month and year.
Getting a more realistic estimate
- Use your own average MPG from the trip computer rather than the manufacturer’s laboratory figure.
- Enter the full return distance when planning a round trip.
- Use the price you normally pay, including any premium-fuel difference.
- Allow for worse consumption in winter, urban traffic or when towing.
Frequently asked questions
Does the calculator use Imperial or US MPG?
Choose Per Litre for UK/Imperial MPG or Per US Gallon for US MPG. Switching the price basis converts both the pump price and MPG figure so the same consumption estimate is preserved.
Does changing currency convert the fuel price?
No. Currency selection changes labels and result formatting only. Enter the fuel price and use every monetary figure in the selected currency.
Why might my actual fuel cost be different?
Real consumption changes with traffic, speed, temperature, driving style, vehicle load, tyre pressure and mechanical condition. Treat the result as a planning estimate.
Can I calculate the cost of a return journey?
Yes. Enter the total outward and return distance, or double the one-way distance before using the result.