Fuel Cost (Trip) Calculator
Estimate the fuel cost of a trip from distance and mileage.
Updates as you type.
How to Calculate Trip Fuel Cost
The fuel cost of a journey depends on three things: how far you travel, how many kilometres your vehicle runs per litre (its mileage), and the current price of fuel. The formula is:
Fuel cost = (Distance ÷ Mileage) × Fuel price per litre
The first part, distance divided by mileage, tells you how many litres the trip needs. Multiplying by the price gives the rupee cost.
Imagine a 480 km trip in a car that delivers 16 km per litre, with petrol at ₹105 per litre:
- Litres needed = 480 ÷ 16 = 30 litres
- Fuel cost = 30 × ₹105 = ₹3,150
Enter your own distance, mileage and fuel price in the calculator above and it returns the litres required and the total cost instantly. The same formula works for petrol, diesel, CNG or electric vehicles — just use the matching mileage and energy price (for CNG use km per kg and price per kg).
Round Trips and Daily Commutes
For a return journey, simply double the one-way distance before applying the formula, or multiply the one-way cost by two:
Round-trip cost = 2 × (One-way distance ÷ Mileage) × Fuel price
Using the earlier example, a return trip of 480 km each way (960 km total) costs:
(960 ÷ 16) × ₹105 = 60 × ₹105 = ₹6,300
For a daily commute, multiply the round-trip cost by the number of working days. If your office is 18 km away (36 km round trip), your bike returns 45 km/l and petrol is ₹105:
- Daily litres = 36 ÷ 45 = 0.8 litres
- Daily cost = 0.8 × ₹105 = ₹84
- Monthly cost (22 working days) = ₹84 × 22 = ₹1,848
This makes it easy to budget for fuel and to compare whether public transport, carpooling or a more fuel-efficient vehicle would save money over a month or year.
Cost Per Kilometre and Smart Comparisons
Cost per kilometre is a handy single number for comparing vehicles, routes or fuel types. It is the fuel price divided by mileage:
Cost per km = Fuel price per litre ÷ Mileage (km/l)
With diesel at ₹92 per litre and a car giving 20 km/l, the running cost is ₹92 ÷ 20 = ₹4.60 per km. A petrol car at ₹105 per litre giving 16 km/l costs ₹6.56 per km — noticeably more for the same distance.
A few practical points improve accuracy:
- Real-world mileage is usually lower than showroom claims, especially in city traffic with frequent stops.
- Air conditioning, overloading, under-inflated tyres and aggressive acceleration all reduce mileage.
- Highway driving at steady speeds typically gives the best mileage.
For a fair comparison, use your own observed mileage: divide the kilometres covered between two full-tank fill-ups by the litres added. Plug that figure into the calculator for a cost-per-km estimate that reflects how you actually drive.
Frequently Asked Questions
Divide the trip distance by your vehicle's mileage to find litres needed, then multiply by the fuel price. For example, 300 km at 15 km/l with fuel at ₹100/litre needs 20 litres and costs ₹2,000.
Fill the tank completely, note the odometer, drive normally, then refill and note the kilometres covered and litres added. Divide kilometres by litres to get your actual km per litre, which is more realistic than the manufacturer's figure.
Double the one-way distance, then apply the standard formula: (total distance ÷ mileage) × fuel price. Alternatively, calculate the one-way cost and multiply by two.
Cost per kilometre is the fuel price divided by mileage. It tells you how much you spend in fuel for every kilometre driven, making it easy to compare different vehicles or fuel types.
Yes. For CNG, use km per kg as the mileage and price per kg as the fuel price. For electric vehicles, use km per kWh and your electricity rate per kWh. The formula works the same way for any energy source.
City traffic, air conditioning, heavy loads, under-inflated tyres and hard acceleration all lower mileage, which raises cost. Using your real observed mileage rather than the showroom figure gives a more accurate estimate.