This fuel cost calculator tells you how much a car journey will cost in petrol, diesel or gas. Enter the distance in kilometres or miles, your vehicle’s fuel economy in litres per 100 km, km per litre, US MPG or UK MPG, and the fuel price per litre or per gallon. It shows the fuel needed, the total cost and the cost per kilometre or mile.
Tick round trip to double the distance, and split the cost between passengers to share a road trip or a car-pool fairly. Units can be mixed freely, so you can enter miles with a price per litre, for example when driving abroad.
How to use the Fuel Cost Calculator tool
- Enter the trip distance and choose km or miles.
- Enter your car’s fuel economy and its unit.
- Enter the fuel price per litre or per gallon and choose a currency symbol.
- Tick round trip if you are coming back, and set how many people share the cost.
- Read the trip cost, fuel needed and cost per person.
Why use ToolOrca Fuel Cost Calculator
- Trip cost, fuel needed and cost per km or mile
- L/100 km, km/L, US MPG and UK MPG
- Price per litre, US gallon or UK gallon
- Round-trip option
- Split the cost between passengers
- Converts your economy to L/100 km and MPG
How trip fuel cost is calculated
With metric units: fuel (L) = distance (km) × consumption (L/100 km) ÷ 100, and cost = fuel × price per litre. A 300 km trip in a car using 7 L/100 km needs 21 litres; at €1.60 a litre it costs €33.60.
With US units: fuel (gal) = distance (miles) ÷ MPG. A 250-mile trip at 30 MPG needs 8.33 gallons; at $3.50 a gallon it costs $29.17.
To convert between the two, L/100 km = 235.215 ÷ US MPG. So 30 US MPG is 7.84 L/100 km, and 7 L/100 km is about 33.6 US MPG. A UK gallon (4.546 L) is bigger than a US gallon (3.785 L), so the same car shows a higher MPG figure in the UK.
Tips to spend less on fuel
Real-world consumption is often 10%–20% higher than the official figure, especially in city traffic, with a roof box or at motorway speeds. Driving at a steady speed, keeping tyres at the right pressure and removing extra weight all help. For a reliable number, fill the tank, note the distance driven until the next fill, and divide the litres added by the kilometres × 100.
Frequently asked questions
How much fuel does a 500 km trip use?
At 6 L/100 km, 500 × 6 ÷ 100 = 30 litres. At 8 L/100 km it is 40 litres.
How much does it cost to drive 100 miles?
At 25 MPG and $3.50 a gallon, 100 ÷ 25 = 4 gallons, so $14, or 14 cents a mile.
How do I convert MPG to L/100 km?
Divide 235.215 by the US MPG (or 282.481 by UK MPG). 40 US MPG = 5.88 L/100 km.
Does it work for diesel and electric cars?
It works for any liquid fuel: petrol, diesel or LPG. For an electric car, enter kWh per 100 km as the consumption and the price per kWh as the price per litre; the maths is the same.