Fuel Cost Calculator: What Will My Journey Cost?
Enter the distance, your car's fuel economy and the pump price to see what the journey costs.
| Fuel used | 11.4 litres |
|---|---|
| Cost per mile | 15.9p |
| The same journey in an electric car (3.5 miles per kWh at 26.3p) | £7.52 (7.5p a mile) |
| Saving with an electric car | £8.39 a journey |
Fuel economy is in UK miles per gallon, and real-world figures are usually lower than the official ones. The electric figure is home charging only; public chargers cost more. Find the pump price on the day.
How the fuel cost is worked out
Fuel used (in litres) = distance ÷ miles per gallon × 4.546 (litres in a UK gallon). Cost = litres × price per litre. For example, a 100-mile journey at 40 mpg uses 11.4 litres, which at 140p a litre costs about £15.91.
Ways to cut fuel costs
- Drive smoothly. Hard acceleration and braking burn more fuel.
- Check your tyre pressure. Under-inflated tyres increase consumption.
- Slow down on motorways. Fuel use rises quickly above about 60 mph.
- Remove roof boxes and extra weight when you are not using them.
Electric car running costs
Charging at home costs about 26.32p per kWh at the Ofgem price cap average. See electric car charging costs, or compare the cost of running household appliances in the running cost tables.
Sources: Ofgem: energy price cap. Figures last checked on 8 October 2026.
Frequently asked questions
How do I work out the fuel cost of a journey?
Divide the miles by your car's miles per gallon, multiply by 4.546 to get litres, then multiply by the price per litre.
How many litres are in a gallon?
A UK (imperial) gallon is 4.546 litres. MPG figures on UK cars use this gallon, not the larger US gallon.
How much does it cost to drive 100 miles?
At 40 mpg and 140p a litre, 100 miles costs about £15.91. Change the figures to match your car and the pump price.
Is an electric car cheaper to run?
Charging at home is usually much cheaper per mile than petrol or diesel. At 26.32p per kWh and 3.5 miles per kWh, 100 miles costs about £7.52. Public rapid chargers cost more.
More from UK Answers
Figures are for the 2026/27 tax year from official sources and are estimates for guidance only, not financial or legal advice. Printed from ukanswers.co.uk.