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Estimated fuel used
Fuel Cost Calculator
Road-trip budgets and commuting comparisons both need a realistic fuel number. This fuel cost calculator combines distance, vehicle efficiency and the price per litre to estimate total fuel spend. Use it before a long drive or when weighing a longer route against a shorter but more expensive one so the fuel line item in your budget is grounded in arithmetic rather than guesswork.
Please enter valid values.
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Estimated fuel cost
How to Use the Fuel Cost Calculator
- Enter the total distance of the trip and choose kilometres or miles.
- Enter your vehicle’s fuel efficiency and choose L/100 km, km/L or MPG (imperial or US).
- Enter the fuel price per litre and choose a currency.
- Calculate to see estimated fuel volume and total cost.
Enter the trip distance and choose kilometres or miles, then enter your car’s fuel efficiency and choose L/100 km, km/L, MPG (imperial) or MPG (US). An imperial gallon (4.546 litres) is larger than a US gallon (3.785 litres), so the same car shows a higher MPG (imperial) figure than MPG (US). Enter the price per litre and pick a currency. The calculator shows the fuel used in litres and the estimated fuel cost. For a round trip, enter the total distance for both ways.
Fuel Cost Calculator Formula Explained
Cost = (Distance ÷ Efficiency) × Price per Unit
First compute fuel volume required. For km per litre efficiency, volume equals distance divided by efficiency. For litres per 100 km, volume equals (distance divided by 100) times the rate. Multiply volume by the price per litre. For MPG, the calculator first converts to L/100 km: 235.2 ÷ MPG for US gallons, or 282.5 ÷ MPG for imperial gallons. Miles are converted to kilometres by multiplying by 1.609.
With L/100 km, the fuel used is distance ÷ 100 × efficiency. With km/L, it is distance ÷ efficiency. The cost is the fuel used times the price per litre. One fixed efficiency is used for the whole trip, so city driving, heavy loads and air conditioning can change the real figure. Tolls and parking are not included.
Fuel Cost Calculator Example Calculation
A 600 km round trip in a car averaging 6 L/100 km needs about 36 litres of fuel. At €1.70 per litre the fuel cost is roughly €61. Motorway versus urban mix can change real consumption, so run a second scenario with a higher L/100 km figure for congestion.
Worked example: 600 km, 6 L/100 km and €1.70 per litre give 36.00 L and a cost of €61.20. With km/L instead, 450 km at 15 km/L and €1.85 per litre gives 30.00 L and €55.50. In miles, 100 miles at 40 MPG (imperial) uses 11.37 L, which costs €16.48 at €1.45 per litre.
When to use this tool
Use this for holiday road trips, commuting comparisons, and company mileage planning.
Key Features & Benefits of This Fuel Cost Calculator
- Kilometres or miles — enter the trip distance in whichever unit you use.
- Four efficiency units — L/100 km, km/L, MPG (imperial) and MPG (US), with the larger imperial gallon handled separately from the US gallon.
- Fuel used and trip cost — see the litres needed and the estimated cost at your price per litre.
- Round trips — enter the distance for both ways to cost the whole journey.
- Instant, free and private — runs entirely in your browser, no sign-up, nothing stored.
Good to know
Fuel prices vary significantly between countries and regions and between motorway and local stations. Update the price field with a realistic local average before long trips.
Fuel Cost Calculator — FAQs
Should I use city or highway efficiency?
Use a blended figure that matches the mix of roads on your route, or run two scenarios for a range.
Does this include tolls or parking?
No. Add those costs separately for a full trip budget.
Why is my real cost higher?
Traffic, cargo weight, driving style, tyre pressure and air conditioning all reduce real-world efficiency versus the sticker number.
Can I compare two cars?
Run the calculator twice with each car’s efficiency and the same distance and fuel price, then compare totals.
How do I calculate fuel cost for a trip?
Divide the distance by your fuel efficiency to get the litres needed, then multiply by the price per litre. With L/100 km, litres = distance ÷ 100 × efficiency. In the worked example, 600 km at 6 L/100 km needs 36 litres, which costs €61.20 at €1.70 per litre.
How do I convert MPG to L/100 km?
For US MPG, divide 235.2 by the MPG figure. For imperial MPG, divide 282.5 by it. For example, 40 MPG (imperial) is about 7.1 L/100 km and 40 MPG (US) is about 5.9 L/100 km. The calculator does this for you when you choose an MPG unit.
Calculate fuel cost per kilometre or mile
Fuel cost per kilometre = (litres per 100 km ÷ 100) × price per litre. At 6 L/100 km and 1.70 per litre, the cost is 0.102 per km, or 10.20 per 100 km. A 600 km trip costs 61.20. Multiply the cost per kilometre by 1.609344 for the cost per mile.
If your station quotes a price per gallon, convert it to a price per litre before entering it: divide a US-gallon price by 3.785411784, or an imperial-gallon price by 4.54609. Selecting MPG changes the efficiency unit, not the price input.
For a return trip, include both journeys in the distance. To split a trip cost, divide the fuel result by the number of people sharing it, then add tolls and parking separately.