Journey cost
£19.43
Fuel cost calculator
What a journey or a fill-up costs at today's prices. The price box starts at the UK average from official retailer data on 4 November 2026: 171.0p unleaded and 198.2p diesel.
Fuel used
11.4 L
Cost per mile
19.4p
50 litre fill
£85.50
Litres = miles ÷ mpg × 4.546. The price starts at today's UK average for the grade and can be changed to the price on your local totem.
Fuel cost: quick answers
How much does it cost to drive 100 miles?
At today's UK average of 171.0p for unleaded, a car doing 40 mpg uses 11.4 litres over 100 miles, which costs £19.43 (19.4p a mile). The same trip on diesel at 198.2p costs £22.53.
How much does a full tank of petrol cost?
A 50-litre tank of unleaded costs £85.50 at today's UK average of 171.0p. At the cheapest station in our data (150.9p) the same fill is £75.45, a saving of £10.05.
How do you work out fuel cost per mile?
Divide the miles by your car's mpg to get gallons, multiply by 4.546 to turn UK gallons into litres, then multiply by the price per litre. The calculator above does that with today's average price filled in, and you can change it to the price on your local totem.
Pay less for the same journey
The price is the only input you can change at the pump. Find the cheapest station near you, which also says whether a cheaper forecourt is worth the extra miles, put your postcode into the fuel saving calculator to see what that adds up to over a year, or compare supermarket prices and motorway prices before a long trip.