Fuel Cost Calculator
Calculate the fuel cost for any trip based on distance, fuel efficiency, and current fuel prices.
About the Fuel Cost Calculator
India's fuel prices are revised daily by oil marketing companies (IOCL, BPCL, HPCL), with petrol ranging from ₹90 to ₹110 per litre depending on state taxes, and diesel typically ₹5-10 lower. For regular commuters and long-distance drivers, calculating fuel cost per kilometre makes the true cost of vehicle ownership visible - and reveals opportunities to reduce it.
The single biggest variable most drivers ignore is the gap between ARAI-claimed efficiency and real-world efficiency. ARAI figures are tested under controlled conditions that do not reflect Indian city traffic - heavy braking, idling at signals, AC usage, and high ambient temperatures. In practice, a car claiming 18 km/L ARAI might achieve 12-14 km/L in Bengaluru or Mumbai traffic. Using ARAI figures in your calculation leads to a 25-30% underestimate of actual fuel spend.
The petrol vs CNG vs EV comparison has become genuinely interesting in 2025-26. CNG at roughly ₹80-90 per kg delivers approximately 20-25 km/kg for most cars, making cost per km roughly half of petrol. EVs at current electricity rates (₹7-9/kWh average) cost approximately ₹1-2 per km versus ₹6-8 per km for petrol. The switch economics depend on your annual kilometres - high-mileage drivers (15,000+ km/year) see EV payback in 3-5 years, while low-mileage drivers may never break even on the premium.
Fuel Cost Calculation
Fuel needed = Distance / Fuel efficiency (km/L) - Fuel cost = Fuel needed x Price per litre
Cost per km = Fuel price / Fuel efficiency - For EVs: Cost per km = Electricity rate (Rs/kWh) x Consumption (kWh/100km) / 100 - Real-world efficiency is typically 10-25% lower than ARAI-claimed figures
Worked Example
Monthly commute 1,200 km at 14 km/L petrol car, petrol at ₹104/litre
Fuel needed = 85.7 litres - Monthly fuel cost = ₹8,913 - Cost per km = ₹7.43
Tips & Insights
- 1
Real-world fuel efficiency in city driving is 15-25% below ARAI-claimed figures. Use the reading from your trip meter over a full tank cycle for an accurate baseline - then enter that number here instead of the ARAI claim.
- 2
Tyre pressure at the manufacturer-recommended level (usually 32-36 PSI) improves fuel efficiency by 2-3% and extends tyre life. Check monthly or before any long trip - under-inflated tyres are the most common cause of unexplained efficiency drops.
- 3
Air conditioning increases fuel consumption by 10-20% at city speeds. In stop-and-go traffic, consider using ventilation mode on short trips under 10 minutes where the cabin can cool through airflow rather than active cooling.
- 4
At ₹95/L petrol and ₹7/kWh electricity, an EV consuming 15 kWh/100km costs ₹1.05/km versus ₹6.33/km for a petrol car at 15 km/L. For 15,000 km/year, that is ₹79,000 saved annually - enough to recover a significant portion of the EV premium within 3-4 years.
- 5
Highway driving at 80-90 km/h is 20-30% more fuel-efficient than city stop-and-go traffic at the same distance. If you have a highway commute option, even one day per week of highway vs city driving reduces monthly fuel cost meaningfully.
- 6
CNG conversions pay off in approximately 1.5-2 years for high-mileage vehicles. At ₹85/kg CNG and 22 km/kg, cost per km is ₹3.86 versus ₹6.33/km for petrol. The Rs 60,000-80,000 kit cost is recovered at roughly 30,000-35,000 km of driving.
- 7
Use the monthly projection row to see your annual fuel spend. If that number surprises you, compare it against the annual EMI saving from not owning a second vehicle - for many urban families with good public transport access, the fuel cost analysis alone makes the second-car decision obviously uneconomical.
Why this matters for you
Fuel is the largest variable operating expense for the 30 crore+ registered vehicles in India. For a middle-class commuter driving 1,200 km per month at ₹7/km, annual fuel cost is ₹1,00,000. A 15% improvement in efficiency - achievable through better driving habits, proper tyre pressure, and choosing the right vehicle - saves ₹15,000 per year. At 10 years, that is ₹1.5 lakh simply from understanding and managing your fuel spend.
The vehicle purchase decision is one of the largest financial commitments most Indian families make. EMI calculations tell you the acquisition cost, but fuel cost per km over the vehicle's lifetime can dwarf that figure. A car with a ₹2 lakh lower purchase price but 3 km/L worse efficiency costs more over 10 years and 1,50,000 km at current fuel prices. This calculator makes the lifetime cost comparison explicit and changes how you evaluate vehicle choices.
India's EV transition is accelerating, with sales crossing 20 lakh units in 2024-25. The primary barrier to adoption is not infrastructure or range anxiety for most urban buyers - it is uncertainty about the true cost saving. This calculator's petrol vs CNG vs EV comparison quantifies the economics at your actual mileage and your state's electricity rate, turning an abstract 'EVs are cheaper' claim into a specific rupee figure per month.
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Frequently Asked Questions
How do I calculate fuel cost for a trip?+
Fuel needed = Distance ÷ Fuel Efficiency (km/L). Fuel Cost = Fuel Needed × Price per Liter. Example: 300 km trip at 15 km/L with petrol at ₹105/L → 20 liters → ₹2,100 total.
What is a good fuel efficiency for a car in India?+
Petrol hatchbacks average 15–20 km/L, sedans 12–17 km/L, SUVs 10–15 km/L. Diesel vehicles run 5–8 km/L higher. Hybrids and EVs are significantly more efficient.
How can I improve my car's fuel efficiency?+
Maintain tyre pressure (10% under-inflation reduces efficiency by 2–3%), drive at 60–80 km/h (most efficient range), avoid sudden acceleration and heavy braking, and service regularly (clean air filter, fresh oil).
How do I convert km/L to L/100km?+
L/100km = 100 ÷ km/L. For example, 15 km/L = 100÷15 = 6.67 L/100km. Higher km/L = better efficiency; lower L/100km = better efficiency.
How can I improve my vehicle fuel efficiency to reduce costs?+
Proven fuel-saving techniques: Tyre pressure - under-inflated tyres by 10 PSI reduces fuel efficiency by 3-4%, so check monthly. Speed - driving at 80-90 km/h on highways is 15-20% more efficient than 110 km/h. AC vs windows - at speeds under 60 km/h, open windows are more efficient; above 80 km/h, AC is better as open windows create drag. Smooth driving - avoiding aggressive braking and acceleration can improve mileage by 20-30%. Removing unnecessary weight from the boot - 50 kg extra reduces mileage by 1-2%. Engine air filter - a clogged filter reduces mileage by up to 10%.
How do I calculate monthly commute fuel costs?+
Monthly commute cost = (One-way distance x 2 x Working days) / Fuel efficiency x Fuel price. Example: 15 km each way, 22 working days/month, 15 km/L petrol, Rs. 105/L. Monthly distance = 15 x 2 x 22 = 660 km. Fuel needed = 660 / 15 = 44 L. Monthly cost = 44 x Rs. 105 = Rs. 4,620. This calculation is useful for comparing transport options: at Rs. 4,620/month fuel, a Metro pass at Rs. 1,200/month saves Rs. 3,420/month - enough to justify switching even accounting for convenience. Use the trip projection panel in this calculator and enter your daily round-trip distance.
How do petrol, diesel, and CNG compare in running costs?+
Running cost depends on fuel price and vehicle efficiency. Typical comparison for 10,000 km/year: Petrol at Rs. 105/L at 15 km/L = Rs. 7/km. Diesel at Rs. 92/L at 20 km/L (diesel engines run 20-25% more efficiently) = Rs. 4.60/km. CNG at Rs. 76/kg at 25 km/kg = Rs. 3.04/km. Annual costs: Petrol Rs. 70,000, Diesel Rs. 46,000, CNG Rs. 30,400. CNG saves Rs. 39,600/year over petrol. However, factory-fitted CNG cars cost Rs. 80,000-1,50,000 more at purchase. At 10,000 km/year savings of Rs. 39,600, that premium pays back in roughly 2-4 years depending on the specific model and driving pattern.