What is the Fuel Cost?
Fuel cost is distance divided by mileage, times the pump price. It is the largest running cost for most private vehicles, and the one people most consistently underestimate because it is paid in small amounts.
The annual figure is usually the eye-opener: a 40 km daily commute at 15 km/l can quietly cost more than ₹1.4 lakh a year.
Formula & worked example
Cost = Litres × Price per litre
Worked example: a 40 km round trip at 15 km/l with petrol at ₹105 → 2.67 litres, costing ₹280 per trip. Over 44 trips a month that is ₹12,320, or about ₹1.48 lakh a year — the cost per km works out to ₹7.
How to use this fuel cost calculator
- Enter the total distance per trip, including the return leg.
- Use your vehicle's real-world mileage, which is typically 15–25% below the claimed figure.
- Enter today's pump price.
- Set trips per month — 44 is a typical two-way daily commute.
Smart tips
- Real mileage is usually 15–25% below the brochure figure. Compute yours from tank-to-tank readings.
- Correct tyre pressure alone improves mileage by 3–5%; it is the cheapest fuel saving available.
- Steady speeds of 50–70 km/h are far more efficient than hard acceleration in traffic.
- CNG runs roughly 40–50% cheaper per km than petrol; an EV can be 70–80% cheaper on home charging.
- Compare monthly fuel cost against a monthly transit pass before assuming driving is cheaper.
Frequently asked questions
How do I calculate fuel cost for a trip?
Divide distance by your mileage to get litres needed, then multiply by the price per litre.
How much does fuel cost per km?
At 15 km/l with petrol at ₹105, about ₹7 per km. A 20 km/l bike is closer to ₹5.25, and an EV on home charging around ₹1–1.5.
Is diesel cheaper to run than petrol?
Diesel engines deliver 20–25% better mileage, but the vehicles cost more upfront and service is pricier. Diesel pays off above roughly 15,000–20,000 km a year.
How can I improve my mileage?
Maintain tyre pressure, avoid hard acceleration, remove roof carriers and excess weight, service on schedule, and use AC judiciously in city traffic.
Want the theory behind the numbers? Read our vehicle cost guides on the Money Blog.
Written by Gurjeet Singh, Sharpen Solutions. Last reviewed 30 Sep 2026. How we check these numbers.