Step 1: Enter your monthly driving distance

Type the total kilometres you drive in a typical month or use the slider for a quick estimate. Most urban commuters in Indian cities drive between 800 and 2,000 km per month. If your distance varies between weekdays and weekends, take a simple average. This number matters more than any other input because it determines how quickly a CNG or EV vehicle pays back its purchase premium over a standard petrol car. If you are unsure of your monthly mileage, check your odometer at two consecutive full-tank refills and divide the distance covered by the number of days between them.

Step 2: Choose which fuel types to compare

Toggle the Petrol, Diesel, CNG and Electric buttons to activate or deactivate each fuel type. You can compare all four at once or narrow it to just two. If you are only choosing between petrol and CNG for your next car, deactivating diesel and EV keeps the results focused. Input cards for each active fuel appear immediately so you can adjust every variable independently.

Step 3: Fill in price, mileage and maintenance for each fuel

For petrol and diesel, enter the price per litre in your city. Prices vary significantly across India. Delhi petrol is around ₹96 per litre while Mumbai is around ₹103 and several districts in Rajasthan and Madhya Pradesh cross ₹108. Always use your last fuel receipt for accuracy. Enter your vehicle's observed real-world mileage rather than the ARAI-certified figure, which is typically 15 to 20 percent higher than what you actually see on Indian city roads. For CNG, enter the price per kg at your nearest pump. For electric, enter your home electricity tariff per unit and the vehicle's real-world efficiency in km per kWh. The maintenance field takes a yearly amount covering servicing, oil changes, filters, brake work and tyres.

Step 4: Set your inflation rate and projection period (optional)

Open the Advanced Options section to set an annual fuel price inflation rate. India's petrol prices have risen at an average of 5 to 8 percent per year over the past decade. Using 6 percent gives a conservative but realistic view of how your petrol or diesel bill will grow over the ownership period. You can also choose your projection horizon from 3 to 10 years depending on how long you plan to keep the vehicle. A longer projection makes the financial case for EV or CNG significantly stronger.

Step 5: Read the full comparison results

Results include a winner card showing the cheapest fuel type for your usage, cost per km figures for every active fuel, a visual bar comparison, a full summary table, break-even analysis showing when switching pays off, CO₂ emission bars, and an inflation-adjusted projection chart across your ownership period. The break-even figure is the one number most vehicle buyers miss entirely. It tells you exactly how many months it takes for the lower running cost of a CNG or EV to recover the higher purchase price you paid for it. To explore this further for electric vehicles specifically, our EV vs Petrol Cost Calculator provides a dedicated break-even model with battery degradation, public charging mix and Section 80EEB tax saving included.

Most free fuel cost tools available online show you one thing: your monthly fuel spend for a single vehicle. That number is useful but it answers only a fraction of what you actually need to know before choosing between petrol, diesel, CNG or electric vehicles. Four things change the picture completely and most tools skip all of them.

The calculation is simple enough to do at the fuel pump once you understand it. Fuel cost per km equals the price per unit of fuel divided by how many kilometres your vehicle travels on one unit. Add your monthly maintenance divided by your monthly kilometres to get the complete running cost per km.

The table below uses actual 2025 Indian fuel prices and real-world adjusted mileage for popular vehicles across all four fuel types. These are honest figures, not manufacturer claims. Enter your own exact prices above for personalised results.

The Tata Nexon EV at ₹1.50 per km costs less than one-fourth of what the Hyundai Creta Diesel costs at ₹6.60 per km. At 1,200 km per month that is a difference of ₹6,120 every month in running cost. Over five years, even accounting for the higher purchase price of the Nexon EV, the total ownership cost often works out in the EV's favour for drivers who charge primarily at home. The Ola S1 Air electric scooter at ₹0.55 per km completely redefines what low running cost means for two-wheeler commuters. If you are deciding on a two-wheeler and need loan planning support, our Bike Loan Calculator shows your exact monthly EMI for any scooter or motorcycle budget.

Choosing the cheapest fuel type for your situation depends on three things: how many kilometres you drive each month, whether you have convenient access to home charging or a CNG pump, and how long you intend to keep the vehicle. Here is a practical framework for each fuel type based on real Indian ownership patterns.

The single most overlooked factor in the petrol vs CNG vs EV choice is monthly driving distance. The table below shows annual running cost across all four fuel types at three usage levels using 2025 Indian prices. The difference between 600 km and 2,000 km per month changes which option wins and by how much.

EV wins on annual running cost at every mileage level for home-charging users. The question is always whether the higher purchase price is recovered within your expected ownership period. A buyer driving 600 km per month saves ₹34,000 per year over petrol by choosing an EV. If the EV costs ₹4 lakh more than the petrol equivalent, break-even arrives in about 12 years, which is longer than most car ownership cycles in India. The same ₹4 lakh premium breaks even in just under 4 years at 2,000 km per month. Use our Car Loan Calculator to plan your vehicle purchase budget and our Loan Eligibility Checker to confirm how much you qualify for before visiting the showroom.

Vehicle running cost is one of the largest fixed expenses for most Indian households, typically second only to rent or home loan EMI. A practical budgeting rule is to keep total transport spending including fuel, maintenance and loan EMI within 15 percent of take-home monthly income. If your petrol bill is ₹8,000 per month and your car EMI is ₹12,000, your total transport outgo is ₹20,000, which requires a take-home income of at least ₹1.33 lakh to stay within that threshold. Our Expense Planner helps you map your complete monthly outflows and identify where transport costs can be trimmed. If you are currently servicing a car loan and want to explore closing it early to reduce your monthly commitment, the Loan Prepayment Calculator will show you exactly how much interest you save and how many months you cut off by making a lump-sum payment.

One practical habit that many vehicle owners overlook is setting aside a fixed maintenance fund every month rather than treating servicing as an unexpected expense. Even ₹1,000 per month in a Recurring Deposit earns interest and is ready when your quarterly service or annual tyre replacement arrives. If you are thinking longer term, the savings from switching to a CNG or EV are worth calculating as an investment opportunity. Even ₹3,000 per month in fuel savings redirected into a monthly SIP compounds into a meaningful corpus over 10 to 15 years.

Petrol bikes have a natural cost advantage over petrol cars because of their much higher fuel efficiency. A Hero Splendor at 65 km per litre costs ₹1.60 per km at ₹104 per litre. A Bajaj Pulsar 150 at 45 km per litre costs ₹2.31 per km. Compare these to a typical petrol car at 15 km per litre costing ₹6.93 per km and the gap is clear. However, an EV scooter like the Ola S1 Air at ₹0.32 per km in charging cost actually beats every petrol two-wheeler on the market today. For city commuters covering 800 to 1,500 km per month on short daily trips, an EV scooter has the lowest total cost of ownership of any personal vehicle currently available in India. This calculator works for two-wheelers and bikes exactly as it does for cars. Simply enter your bike's mileage in the petrol field or your scooter's efficiency in the EV field to see a side-by-side comparison.

Even if switching fuel types is not an option right now, there are practical steps that reduce your cost per km on the vehicle you already own. Tyre pressure is the most commonly neglected factor. Tyres that are 5 PSI underinflated reduce fuel efficiency by 1 to 3 percent and also increase tyre wear. Checking pressure fortnightly at a petrol pump takes two minutes and costs nothing. Driving at steady speeds between 50 and 80 km per hour on highways improves mileage by 10 to 15 percent compared to frequent acceleration and hard braking. Air filter replacement every 15,000 km is one of the cheapest service items with a measurable impact on mileage in Indian road conditions where dust clogging is common. Using the engine oil grade specified in your owner manual rather than a thicker grade also reduces internal friction and marginally improves efficiency.

For anyone planning larger financial goals alongside a vehicle switch, our Financial Independence Calculator shows how redirecting even ₹3,000 per month in fuel savings into long-term investments changes your retirement or financial freedom timeline. And if you want to understand how the total value of your running cost savings compounds over years, our CAGR Calculator helps you put a precise growth figure on any annual saving.