Fuel Cost Calculator
Estimate fuel needed and trip cost from distance, mileage in km/L, L/100 km or mpg and the fuel price, with return trips and cost sharing.
Tool guide
What this tool does
The Fuel Cost Calculator works out how much fuel a journey uses and what it costs. It accepts kilometres or miles, efficiency in km/L, L/100 km, US mpg or UK mpg, prices per litre or gallon, repeated trips such as a monthly commute and splits the cost between passengers.
Knowing the fuel cost of a trip helps you budget for a road holiday, compare driving with a train or flight, agree a fair share with fellow passengers or work out the real cost of a daily commute. The difficulty is that fuel economy is quoted in different ways around the world: km per litre in India, litres per 100 km in Europe and Australia, and miles per gallon in the US and UK, where the US and imperial gallons differ in size.
The calculator converts everything to litres per kilometre. One US gallon is 3.785 litres, one UK gallon is 4.546 litres and one mile is 1.609 km. Fuel needed = distance × litres per km, and cost = fuel × price per litre. Turn on Return journey to double the distance and use Number of trips for regular journeys, such as 22 working days of commuting.
How to use Fuel Cost Calculator
- Choose the currency and enter the one-way distance in kilometres or miles.
- Enter your vehicle’s fuel efficiency and pick its unit.
- Enter the fuel price and whether it is per litre, US gallon or UK gallon.
- Switch on Return journey if you are coming back the same way.
- Set the number of trips and the number of people sharing the cost.
- Read the total fuel cost, fuel needed, cost per km or mile and cost per person.
Tips for better results
- Use your real-world mileage from a few full-tank fills rather than the official figure, which is usually optimistic.
- Highway driving at steady speeds is usually more efficient than city traffic; motorway speeds above about 100 km/h raise consumption.
- Correct tyre pressure and a lighter load can improve efficiency noticeably.
Common use cases
- Budgeting for a road trip or holiday drive.
- Splitting fuel costs fairly in a car pool.
- Comparing the monthly cost of driving to work with public transport.
- Estimating fuel reimbursement for business travel.
Common mistakes to avoid
- Mixing US and UK gallons; a UK mpg figure is about 20% higher than the US figure for the same car.
- Entering L/100 km as km/L, which inverts the consumption.
- Forgetting tolls and parking, which are not part of fuel cost.
Frequently asked questions
How do I calculate fuel cost for a trip?
Divide the distance by the mileage (km/L) to get litres, then multiply by the price per litre. 700 km at 15 km/L uses 46.67 litres, which costs about 4,807 at 103 per litre.
How do I convert mpg to L/100 km?
For US mpg, L/100 km = 235.21 ÷ mpg; for UK mpg, L/100 km = 282.48 ÷ mpg. The calculator does this automatically.
Can I calculate a monthly commute?
Yes. Enter the one-way distance, switch on Return journey and set Number of trips to your working days, for example 22.
Does it work for electric cars?
Not directly, because they use kWh rather than litres. Use the electricity bill calculator with the car’s kWh per 100 km and your tariff instead.
Feedback & suggestions
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