Fuel cost calculator: what a journey costs
Work out what a journey will cost in petrol or diesel, using your car's fuel economy and today's pump prices.
Fuel cost
£64.42
for 240 miles
- Fuel used
- 32.5 litres
- Cost per mile
- 26.8p
How to work out fuel cost
Divide the distance by your car's miles per gallon to get gallons, multiply by 4.546 to get litres, then multiply by the price per litre. For example, 100 miles in a car that does 45mpg uses 10.1 litres, which costs £17.32 at an average unleaded price of 171.4p.
Current fuel prices
Pump prices (today's UK average): 171.4p a litre for unleaded and 198.4p for diesel. See the full UK Pump Price Index or find the cheapest fuel near you.
Getting more miles from a tank
- Keep tyres at the recommended pressure: under-inflated tyres can cost a few percent in economy.
- Drive smoothly and keep to the speed limit. At 70mph most cars use noticeably more fuel than at 60mph.
- Take off empty roof boxes and bike racks; they add drag at speed.
Frequently asked questions
›How many litres are in a gallon?
A UK (imperial) gallon is 4.546 litres. US gallons are smaller, 3.785 litres, so US MPG figures look lower for the same car.
›How do I find my car's MPG?
Your car's trip computer shows the average you actually get. You can also brim the tank, reset the trip meter, then divide the miles driven by the litres needed to refill, and multiply by 4.546.
›How much should I charge passengers for petrol?
Splitting the fuel cost equally between everyone in the car is the usual approach. If you're driving for work, HMRC lets employers pay 5p a mile per passenger tax-free.