Work out the fuel cost of any trip
Planning a road trip, a daily commute or a weekend drive to see family? This fuel cost calculator tells you how much petrol, diesel, gas, CNG or electricity a journey will use and what it will cost. Enter the distance, your vehicle’s efficiency and the price at the pump or charger, add tolls or parking if you like, and you get the trip cost, the fuel cost per kilometre or mile, and each passenger’s share.
It speaks every unit people actually use: kilometres or miles, km/L (common in India), L/100 km (Europe, Australia, Canada), and miles per gallon in both US and UK gallons, with prices per litre or per gallon in rupees, dollars, pounds, euros and more. CNG is priced per kg (km/kg) and electric cars per kWh (kWh/100 km, km/kWh or mi/kWh) with a charging loss. Tick “Compare with a second vehicle” to see whether petrol, diesel, CNG or an EV is cheaper to run, what that saves in a year, and how long the saving takes to repay a higher purchase price.
How to use the Fuel Cost Calculator
- Enter the one-way trip distance and choose km or miles. Tick “Round trip” if you are coming back the same way.
- Choose the fuel type — petrol or diesel, CNG or electric — so the right units appear.
- Enter your fuel efficiency and its unit; the other units are shown underneath as a check.
- Enter today’s fuel price, its unit and your currency.
- Set how many people are sharing, and add tolls, parking or other trip costs to split them too.
- Optionally tick “Compare with a second vehicle”, enter its fuel type, efficiency and price, the distance you drive a year and the extra price paid for it.
- Press “Copy summary” to paste the numbers into a group chat.
Fuel Cost Calculator features
All efficiency units
km/L, L/100 km, US and UK mpg, converted exactly (1 mile = 1.609344 km, 1 US gallon = 3.785 L, 1 UK gallon = 4.546 L).
Round trips and passengers
Double the distance with one tick and split the cost between up to 50 people.
Cost per km and per mile
See the running cost of the vehicle in both units — handy for mileage claims and comparing cars.
Petrol, diesel, CNG or EV
Litres or gallons, kg of CNG, or kWh with charging losses — in the same calculator.
Two-vehicle comparison
Cost per trip, per 1,000 km or miles and per year, plus the break-even time on a price premium.
The fuel cost formula
Fuel cost is simply fuel used × price per unit of fuel, and fuel used = distance ÷ fuel efficiency. The calculator converts everything to kilometres and litres internally, so you can mix units freely.
Example (India): a 350 km drive in a car that does 15 km/L uses 350 ÷ 15 = 23.33 litres. At ₹103 a litre that is ₹2,403 one way, or ₹4,807 for the round trip — about ₹1,202 each for four friends, or ₹6.87 per km.
Example (US): 220 miles at 28 mpg uses 7.86 US gallons; at $3.40 a gallon the trip costs $26.71. L/100 km works the other way round (lower is better): 7.5 L/100 km over 300 km uses 22.5 litres.
Petrol vs CNG vs EV: cost per km and break-even
Cost per km = price per unit ÷ efficiency: ₹100 petrol at 10 km/L is ₹10 a km; ₹80 CNG at 25 km/kg is ₹3.20; an EV using 15 kWh per 100 km on ₹8 electricity with a 10% charging loss is 0.15 ÷ 0.9 × 8 = ₹1.33. Over 10,000 km a year the CNG car saves ₹68,000 of fuel, so a ₹50,000 higher price is paid back in about 0.7 years (9 months, or 7,353 km): break-even = extra price ÷ yearly saving.
Fuel is only part of the story — servicing, insurance, tyres and resale value differ too. The cost per km calculator adds them, and the EV charging cost calculator prices home and public charging.
US mpg vs UK mpg
A UK (imperial) gallon is about 20% larger than a US gallon, so the same car shows a higher mpg figure in Britain: 40 mpg (UK) is about 33.3 mpg (US) and 7.06 L/100 km. Pick the gallon that matches where your figure came from. UK pumps sell by the litre, so British drivers combine mpg (UK) with a price per litre. For other conversions, use the fuel economy converter.
| km/L | L/100 km | mpg (US) | mpg (UK) |
|---|---|---|---|
| 10 | 10.0 | 23.5 | 28.2 |
| 15 | 6.67 | 35.3 | 42.4 |
| 20 | 5.00 | 47.0 | 56.5 |
| 25 | 4.00 | 58.8 | 70.6 |
Getting an accurate estimate
- Use real-world mileage. Official ratings (ARAI, EPA, WLTP) come from lab cycles; real driving often uses 10–20% more fuel.
- Allow for traffic, AC and luggage. Stop-start driving, air conditioning and a full car all raise consumption; steady speeds around 80–90 km/h are usually most efficient.
- Planning a whole holiday? Use the travel budget planner for stays and food, or the split bill calculator for uneven shares.
- Driving abroad? Convert the fuel price into your home currency with the currency converter.
Fuel Cost Calculator FAQ
How do I calculate fuel cost for a trip?
Divide the distance by your fuel efficiency to get the fuel needed, then multiply by the fuel price. A 500 km trip at 20 km/L needs 25 litres; at ₹100 a litre it costs ₹2,500. The fuel cost calculator does this in any unit.
How do I find my car’s real mileage?
Fill the tank, reset the trip meter, drive normally, then fill up again. Divide the kilometres driven by the litres it took to get km/L.
Is diesel cheaper than petrol for long trips?
Often, because diesel cars usually travel further per litre, but it depends on prices and the vehicles. Tick “Compare with a second vehicle”, enter each car’s mileage and fuel price, and see the difference per trip and per 1,000 km.
Does this include tolls and electric cars?
Yes: add tolls, parking, food or a stay under “other trip costs” and they are added to the total and split. Choose Electric to price an EV per kWh. Maintenance and depreciation are not included.
Is CNG cheaper than petrol?
Per km, usually: ₹80 CNG at 25 km/kg is ₹3.20 a km against ₹10 for ₹100 petrol at 10 km/L. Enter your own prices and the CNG car’s extra price to see how long the saving takes to repay it.
Are the results exact?
They are estimates from your figures. Real use varies with traffic, speed, weather and load, so add about 10% when budgeting.