Fuel Cost Calculator
Calculate your petrol or diesel cost for a trip using travel distance, vehicle mileage and price per litre. Estimate fuel needed, cost per kilometre, round-trip expenses and each traveller's share — whether you're driving a car, SUV or bike.
Calculate your trip fuel cost
Enter your planned one-way distance, actual mileage and local pump price. Change units as needed.
Optional trip budget & cost sharing
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Estimates depend on actual vehicle mileage, route and pump price. Currency selection changes display only; it does not convert exchange rates.
Fuel cost formula: for kilometres and km/L, fuel needed (litres) = trip distance ÷ mileage. Total fuel cost = litres needed × price per litre. For example, 300 km ÷ 15 km/L = 20 L; at ₹105/L, fuel costs ₹2,100.
What is a fuel cost calculator?
A fuel cost calculator helps estimate the amount of petrol or diesel your vehicle may need for a trip and the money you could spend at the fuel station. It combines journey distance, real-world vehicle fuel efficiency and the fuel price entered by you.
This calculator also helps plan return journeys, monthly driving expenses and shared road-trip costs. It keeps the fuel-only amount separate from optional tolls and parking, making the final budget easier to understand.
How to calculate trip fuel cost
- Enter the one-way distance and choose kilometres or miles.
- Enter your vehicle's actual mileage and select km/L, L/100 km or US MPG.
- Enter the latest price you know for your petrol or diesel, including whether the price is per litre or per US gallon.
- Choose a one-way or round-trip journey, then optionally add tolls and parking.
- Enter the number of people sharing the trip and trips per month if relevant.
- Calculate to see fuel required, estimated petrol/diesel cost, price per kilometre, total trip budget and per-person share.
Fuel cost calculator formulas
Fuel (L) = Distance (km) ÷ Mileage (km/L)Fuel (L) = Distance (km) × L/100 km ÷ 100Fuel (US gallons) = Distance (miles) ÷ US MPGMultiply the estimated fuel quantity by the price in the matching unit. One mile equals 1.609344 km, while one US liquid gallon equals 3.785411784 litres. This page converts the units before calculating the price, so you can combine kilometres with US MPG or miles with km/L.
How to calculate fuel cost per kilometre
When mileage is measured in km/L and fuel is priced per litre, fuel cost per km = price per litre ÷ mileage. With petrol at ₹105/L and a car averaging 15 km/L, the estimated fuel cost is ₹7 per kilometre.
Fuel cost calculation example
Suppose you're planning a 300 km drive in a car that averages 15 km/L and the local petrol price you enter is ₹105 per litre. The trip needs approximately 20 litres, so the estimated fuel-only cost is ₹2,100. A return journey over the same route doubles that estimate when mileage and price remain constant.
| Example | One-way trip | Round trip |
|---|---|---|
| Distance | 300 km | 600 km |
| Mileage | 15 km/L | 15 km/L |
| Fuel price (illustrative) | ₹105/L | ₹105/L |
| Fuel required | 20 litres | 40 litres |
| Fuel cost | ₹2,100 | ₹4,200 |
| Cost per km | ₹7 | ₹7 |
The ₹105 figure is only an example, not a claim about today's petrol price. Actual rates differ by location, outlet and fuel type.
Petrol vs diesel fuel cost: what changes?
The calculation method is the same for petrol and diesel vehicles. The main differences are the fuel price you enter and the mileage your vehicle actually achieves. A diesel SUV and a petrol hatchback can have different per-kilometre costs even on exactly the same route.
To compare two vehicles fairly, calculate them using the same distance, journey type and realistic mileage, then change the fuel price as appropriate. This calculator covers liquid fuels priced by litre or US gallon, not CNG measured in kilograms or electric vehicles measured in kWh.
Round-trip fuel cost and passenger sharing
A round trip includes travel to the destination and back. If the return journey follows a similar route, choose Round trip to double the one-way distance automatically. Add any tolls and parking for the entire selected journey rather than automatically doubling those fees.
When friends share the cost, the calculator divides the total planned trip budget — fuel plus the optional expenses — equally among the number of people entered. It doesn't assume everyone is paying for the same amount of fuel separately.
Monthly petrol cost for office or regular travel
For a repeated commute or delivery route, enter how much one trip costs and how many times it takes place each month. The monthly figure equals the selected trip budget multiplied by trips per month, while the annual estimate uses 12 months at the same frequency.
These are planning figures, not predictions. Actual monthly costs change with holidays, traffic, pump prices, route distance and your vehicle's mileage.
How to measure your vehicle's real mileage
- Fill the fuel tank to a consistent level and record the odometer reading.
- Drive normally for a representative distance.
- Refill to the same level and note the litres added and distance travelled.
- Divide kilometres travelled by litres refilled to estimate your real-world km/L.
Real-world mileage can differ from a brochure rating due to traffic, tyre pressure, air conditioning, road gradient, vehicle load and driving style. Using an actual measured value usually makes a trip budget more useful.
What affects petrol and diesel consumption?
Traffic and speed
Stop-start traffic, idling and high speeds can increase fuel use compared with smooth driving.
Vehicle condition
Tyre pressure, maintenance and mechanical condition can affect real-world fuel efficiency.
Route and load
Hills, diversions, passengers, luggage and air conditioning can change the fuel needed.
Common fuel-cost calculation mistakes
- Using brochure mileage: your actual km/L may be lower than the advertised figure.
- Mixing miles and kilometres: convert distance before applying a mileage formula.
- Confusing US gallons with litres: they are different units and cannot be priced interchangeably.
- Forgetting the return journey: round trips usually involve twice the one-way distance.
- Ignoring tolls and parking: fuel cost alone may understate your overall trip budget.
- Assuming live fuel prices: this calculator uses the price you enter, not automatically updated city rates.
Related calculators and road-trip guides
Frequently Asked Questions
How do I calculate fuel cost for a trip?
Divide the kilometres you plan to drive by your vehicle's km/L mileage to calculate litres needed, then multiply that amount by the fuel price per litre.
How much does petrol cost per kilometre?
With km/L mileage, divide the price per litre by the mileage. A vehicle giving 15 km/L at ₹105 per litre has an estimated petrol cost of ₹7/km.
How do I calculate fuel for a round trip?
Enter the one-way distance and choose Round trip. The calculator doubles that distance before estimating the fuel amount and cost.
Can I enter mileage in US MPG?
Yes. Select US MPG, enter your vehicle's US miles-per-gallon value and select your distance and fuel-price units. The calculator converts units internally.
Does this calculator fetch today's petrol or diesel price?
No. Enter the current local pump price yourself. The example values shown are illustrative, not live prices.
Are tolls and parking included?
Only if you enter them. Fuel-only cost remains separate from the optional toll/parking charges and the total trip budget.
How accurate is the fuel cost estimate?
The result depends on the mileage, distance and prices entered. Traffic, hills, load, weather and driving conditions can cause actual fuel usage to differ.
Last updated: October 18, 2026. This is an educational trip-cost estimate based on user-provided data. Prices, efficiency and route conditions are not verified or updated in real time.