Trip fuel cost:
distance ÷ mileage × price

How to calculate trip fuel cost

Trip fuel cost is the fuel you need multiplied by the price of a litre. A 480 km trip at 16 km/L needs 30 litres, and at ₹105 a litre that costs ₹3,150.

The three inputs are the distance in km, the mileage in km/L and the fuel price in rupees per litre. If you do not know your mileage, divide a past distance by the litres you filled.

Plan a round trip and a buffer

Distance is one way unless you say otherwise, so double it for a return journey. A 480 km one-way trip is 960 km for the round trip, which needs 960 ÷ 15 = 64 litres at 15 km/L and costs 64 × 105 = ₹6,720.

Add a margin for traffic, hills, air conditioning and detours. Adding 10% to the distance is a simple habit: 480 km becomes 528 km, and the cost at 16 km/L and ₹105 becomes 33 × 105 = ₹3,465.

Splitting the cost between passengers

Divide the total by the number of people in the car, including the driver if everyone shares fairly. If the ₹3,150 trip has 4 people, each pays 3,150 ÷ 4 = ₹787.50.

Group trips often run into small disagreements, so agree the method before leaving: either an equal share, or a cost per kilometre. Dividing ₹3,150 by 480 km gives about ₹6.56 per km, a figure you can reuse for other trips in the same car.

A practical example: a family drives 250 km to a hill station at 18 km/L. That is 13.89 litres, or ₹1,458.33 at ₹105 a litre. Coming back the same way doubles it to about ₹2,917, and a 10% buffer lifts the budget to roughly ₹3,200 for the full return journey.

If fuel prices change on the way, use the average of the prices you expect to pay. A difference of ₹5 a litre on 30 litres is ₹150, small on one trip but noticeable on a long journey.

Comparing two cars or two routes

Run the calculator twice with different mileages. For 1,000 km at ₹105 a litre, a car doing 14 km/L burns 71.43 litres for ₹7,500, while a car doing 20 km/L burns 50 litres for ₹5,250. Over a year of long trips the gap grows.

A shorter route is not always cheaper if it is slower and stop-start, because real mileage falls in heavy traffic. Use a mileage figure from similar roads, not the car's best claim.

Common mistakes

• Forgetting the return leg and budgeting for half the fuel.
• Using the manufacturer's mileage instead of your own measured figure.
• Entering miles or US gallons. The tool expects km and km per litre.
• Using the price from your home town when fuel is dearer on the highway.
• Treating the result as exact. Speed, load and weather all change it.