Fuel Cost Calculator
Estimate the fuel used and the cost of a journey from the distance, your fuel economy and a fuel price you enter.
Worked example
A car that uses 8 litres per 100 km needs 8 litres for a 100 km journey. At 1.50 a litre, that costs 12. In miles per gallon the idea is the same: 100 miles at 25 mpg (US) uses 4 US gallons.
How we calculated this
Fuel used is the distance multiplied by the fuel the vehicle uses for each unit of distance, and the cost is the fuel used multiplied by your price. Kilometres per litre and miles per gallon are first converted to litres per 100 km, using the same exact conversions as the Fuel Economy Converter. US and Imperial gallons are different sizes, so choose the one your price and your figure use.
A result written as a plain number is exact. A result starting with “≈” has been rounded to 10 significant figures, because its exact decimal never ends or is too long to read comfortably. When an exact value is long, its full digits are shown underneath. The calculation itself is never rounded: only the display is.
What this result means
The result is the estimated cost of the fuel for one journey, using the distance, fuel economy and price you entered.
Common mistakes
- Mixing up US and Imperial gallons. They are different sizes, so choose the one that matches your fuel economy figure and your price.
- Entering a fuel economy in the wrong direction. A lower figure is better in litres per 100 km, but a higher figure is better in miles per gallon.
Assumptions and limitations
- It assumes the same fuel economy for the whole journey. Traffic, speed, load and weather all change real fuel use.
- The price is yours, in any currency. Nothing is looked up, and there is no route planning or vehicle data.