Fuel cost calculator

What a trip costs in fuel

Enter the distance, the car's fuel use per 100 km and the price per litre, and you get the litres burnt and what they cost. Tick the return trip and the distance doubles; enter the number of people and the cost is split between them.

The formula is simple: litres = distance ÷ 100 × consumption, and the cost is litres × price. What makes it useful is the cost per kilometre, which is the figure to compare against a train ticket or a mileage allowance.

Frequently asked questions

Where do I find my car's fuel use?

The trip computer shows a long-term average, which is the honest number to use. The manufacturer's figure is measured in a lab and is usually one to two litres optimistic in real traffic.

Does it work for miles per gallon?

The tool works in litres per 100 km. To convert, divide 235.2 by the mpg figure: 40 mpg is about 5.9 l/100 km.

How do I split the cost fairly?

Enter the number of people including the driver. The card then shows the cost per head — handy when settling up after a shared drive.

Why does motorway driving cost more?

Air resistance grows with the square of speed, so a car burns markedly more at 130 km/h than at 90. If you have both figures from the trip computer, run the calculation twice and compare.