Petrol journey cost

Work out the fuel cost of a petrol journey from the distance, your car's fuel economy and the price at the pump.

Journey distance (miles)Fuel economy (mpg)Petrol price (£/L)

Result

Fuel used

Cost

How to use this calculator

Enter the journey distance in miles.
Enter your car's fuel economy in mpg (UK gallons) — check your dashboard's real-world average if available.
Enter the current petrol price per litre.
Read the fuel used and total cost.

Uses UK gallons (4.54609 litres) — not US gallons, which are smaller.
Real-world fuel economy is usually somewhat lower than the manufacturer's official figure.

Technical details: what the fields mean

Journey distance distanceMiles: Total journey distance, in miles.
Fuel economy mpg: Miles per UK gallon — use your car's real-world average rather than the official spec figure for accuracy.
Petrol price pricePerLitre: Current petrol price, in pounds per litre.

Methodology

Litres used = (distance ÷ mpg) × 4.54609 (litres per UK gallon). Cost = litres used × price per litre.

Worked example

200 mile journey, 45mpg, £1.45/litre

Inputs: distanceMiles=200, mpg=45, pricePerLitre=1.45

Result: 20.2 litres, £29.30

Practical guidance

Motorway driving at a steady speed is usually more fuel-efficient than stop-start urban driving.
Compare to the diesel journey cost calculator if you're deciding between fuel types for a specific journey pattern.

Common mistakes

Using a US gallon figure (3.785L) instead of a UK gallon (4.54609L) — this calculator assumes UK gallons.
Using the manufacturer's official mpg instead of your car's real-world average.

At 45mpg and £1.45/litre, about £29.30.