Fuel trip cost calculator
Enter the distance, how much fuel your car uses and what a litre or gallon costs. You get the fuel the trip needs, the total cost and each person's share, in kilometres and litres or in miles and US gallons.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Pick metric or US units.
- Enter the one-way distance and tick round trip if you are driving back.
- Enter your car’s consumption and the price of fuel per litre or gallon.
- Set how many people share the cost, the driver included.
How it works
- Metric: fuel in litres = distance × consumption ÷ 100, with consumption in L/100 km.
- US: fuel in gallons = distance ÷ mpg.
- Cost = fuel × price; per person = cost ÷ people; per km or mile = cost ÷ distance.
- A round trip simply doubles the distance.
Worked example
A 400 km trip at 7.5 L/100 km needs 400 × 7.5 ÷ 100 = 30 L. At 1.80 per litre the fuel costs 54.00, which is 13.50 each for four people and 0.135 per km. Driving back as well doubles it to 60 L and 108.00. In US units, 250 miles at 30 mpg is 8.33 gallons, and at 3.50 a gallon that is 29.17.
Tips
- Use your own average. Real consumption is often higher than the official figure.
- Prices vary along a route. Motorway stations are usually dearer; use a mix if you know it.
- Add a margin. Traffic, detours and hills use more fuel than a flat estimate.
Frequently asked questions
How is the fuel cost of a trip calculated?
In metric units, litres = distance × L/100 km ÷ 100. In US units, gallons = miles ÷ mpg. The cost is the fuel multiplied by the price. For 400 km at 7.5 L/100 km and 1.80 per litre that is 30 L and 54.00.
What number do I enter for consumption?
Use your car's real average from the trip computer or from filling the tank, not the brochure figure. Motorway speed, heavy loads, roof boxes, cold weather and air conditioning all raise it. The fuel economy converter on this site changes between L/100 km and mpg.
Are the miles-per-gallon figures US or imperial gallons?
US gallons (3.785 litres). A UK or imperial gallon is about 20% bigger, so a UK mpg figure would need converting first.
Does the tool include tolls, parking or wear?
No. It counts fuel only. Tolls, parking, tyres and servicing add to the true cost of driving; the car ownership cost calculator covers the yearly picture.