Fuel Cost Calculator
Work out how much a journey costs in petrol or diesel — enter your distance, fuel economy (mpg) and fuel price to see the cost per trip, per mile and, if you like, per year.
Estimate only. Fuel cost figures are estimates based on the mpg, distance and price you enter — actual costs vary with driving style, traffic, load and current fuel prices. Source (fuel price context): gov.uk weekly road fuel prices.
You'd save £32 a year at the alternative price.
- Check tyre pressures monthly — under-inflated tyres increase rolling resistance and can add around 2% to your fuel use, as well as wearing tyres out faster.
- Roof boxes and roof bars increase drag significantly at motorway speeds — a loaded roof box can add roughly 10-20% to fuel consumption on a motorway journey, so take it off when it's not needed.
- Turn the engine off rather than idling when parked or waiting — modern engines use more fuel restarting from cold than they save by idling for more than about 10 seconds.
How fuel cost is calculated
We convert your journey distance and fuel economy into gallons used (miles ÷ mpg), then into litres using the exact imperial conversion of 4.54609 litres per UK gallon. Multiplying litres by the fuel price in pence per litre gives the journey cost. For a return trip we simply double the distance before costing it. To estimate an annual figure, either enter how many times a week you make the journey (we multiply by 52 weeks) or enter your total annual mileage directly — both use the same per-mile cost.