Fuel needed = distance ÷ fuel average; cost = fuel × price per litre. The calculator handles return trips and splitting the cost between passengers, and a second section finds your km per litre from a full-tank test.
How to calculate trip fuel cost
- Enter the distance, your car’s average in km per litre and the fuel price.
- Tick return trip and set the number of people sharing.
- Read litres needed, total cost and cost per person.
Measure your real fuel average
Fill the tank completely and reset the trip meter. Drive normally, then fill up again and note the litres. Kilometres driven ÷ litres filled = your km/l. Highway driving usually gives a 20–30% better average than city traffic, and air-conditioning lowers it.
Frequently asked questions
How do I convert km/l to L/100 km?
Divide 100 by km/l. 14 km/l = 7.14 L/100 km.
What about mpg?
1 km/l = 2.352 US mpg = 2.825 UK mpg.
Updated October 2026 · Built and tested by Sharjeel Tahir · How our tools are tested