How to use the fuel cost calculator
- Under Units, choose km and km/L, km and L/100 km, or miles and US mpg.
- Enter the Trip distance one way.
- Enter the Fuel efficiency in the matching unit.
- Enter the Fuel price (per litre or per gallon) and choose the Currency.
- Tick Return trip (double the distance) if needed, and set Split between to the number of people sharing.
- Read Trip fuel cost, Fuel needed, Cost per person, the cost per km or mile, and the Distance used.
What it does and when to use it
Before a road trip it helps to know what the fuel will cost, whether you are budgeting a holiday, splitting costs with friends, claiming travel expenses, or deciding between driving and taking the train. The calculator turns three numbers you already know into a trip cost and a fair share for each passenger.
It also helps compare vehicles. Run the same trip with a 12 km/L car and an 18 km/L car to see the difference in money, not just in efficiency figures. For an electric car, the electricity cost calculator works out charging cost from kWh and your tariff. To plan how a regular commute fits your spending, try the budget calculator. And if you split the bill for a meal on the same trip, the tip calculator shares it per person.
How it works
The calculator first doubles the distance if Return trip is ticked. Then it finds the fuel needed:
- km/L or mpg: fuel = distance ÷ efficiency
- L/100 km: fuel = distance × efficiency ÷ 100
and from that:
- Trip fuel cost = fuel × price
- Cost per person = trip cost ÷ people
- Cost per km (or mile) = trip cost ÷ distance
Fuel is shown in litres, or in gallons for the mpg option. Money values are rounded to two decimals.
Worked examples
These figures come from the calculator’s own function.
A 300 km drive in India. km and km/L, 300 km, 15 km/L, ₹100 a litre, one person. Fuel needed 20 L, trip fuel cost ₹2,000.00, cost per km ₹6.67.
A US road trip, there and back. Miles and US mpg, 250 miles each way with Return trip ticked, 30 mpg, $3.50 a gallon, split between 2. Distance 500 miles, fuel 16.67 gal, trip cost $58.33, cost per person $29.17.
A European trip shared by three. km and L/100 km, 450 km, 6.5 L/100 km, €1.80 a litre. Fuel needed 29.25 L, trip cost €52.65, €17.55 each.
Limits and tips
- Efficiency varies. City traffic, speed, air conditioning, load and hills all change real consumption. Add a margin for long trips.
- Prices change between fuel stations and over time; use a recent local price.
- Only fuel is counted, not wear, tolls or parking.
- Everything is calculated in your browser.
Frequently asked questions
Which units should I choose?
Where do I find my car's real fuel efficiency?
Does it work for UK miles per gallon?
Does it include tolls or parking?
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