With petrol and diesel prices staying high across India, more drivers are shifting to CNG every year. A CNG-run car can cost 40–60% less per kilometre than petrol, and CNG stations have expanded rapidly across Delhi-NCR, Mumbai, Pune, Gujarat, and other major cities, making it a practical daily-driving option rather than a niche choice.
But the real savings depend on your specific car’s mileage, your daily driving distance, and current local CNG prices — which is why a one-size-fits-all comparison rarely tells the full story. That’s exactly what this CNG calculator is built for: enter your actual car model, mileage, and local fuel prices to get a real cost comparison between CNG, petrol, and diesel, instead of relying on generic estimates.
Prices and mileage data last reviewed: [July 2026]
Free CNG Cost & Savings Calculator
Calculate CNG, Petrol, and Diesel running costs instantly with India’s most comprehensive car mileage database.
Enter Car Details & Prices
Adjust this mileage freely. Selecting a different car above will automatically pre-fill its standard mileage of 31.12 km/kg here, which you can customize anytime!
Compare Running Costs Instantly
Enter your estimated distance (daily, monthly, or annual) on the left and click Calculate Cost to reveal premium savings metrics and fuel comparison charts.
Calculation Results
Fuel Cost Comparison
Visualizing total expenses for traveling X km on different fuel types.
By running on CNG over Petrol, you instantly save ₹0 pocket cash! That represents a massive reduction in total fuel expenditures.
How This CNG Calculator Works
We keep the calculation transparent so you know exactly what you’re looking at:
CNG Calculator Formula used:
- Cost per km (any fuel) = Fuel Price (₹/unit) ÷ Mileage (km/unit)
- Total cost = Cost per km × Distance entered
- Savings = Petrol/Diesel total cost − CNG total cost
Where our data comes from:
- Mileage figures are based on ARAI (Automotive Research Association of India) certified ratings and manufacturer-published specifications for each car model in our database.
- Default fuel prices are indicative averages; we recommend updating them with your local pump/station price for the most accurate result, since CNG and petrol prices vary by state and city.
- All figures are editable — if your car’s real-world mileage differs from the certified figure (which is common), you can adjust it manually before calculating.
A note on accuracy: ARAI mileage is tested under controlled conditions and is usually 15–25% higher than real-world city driving mileage. We recommend using your own recorded mileage if you already own a CNG vehicle, or checking owner forums for real-world figures on the model you’re considering.
Real-World Mileage Comparison Table
Claimed vs Real-World CNG Mileage (Popular Models)
| Car Model | ARAI Claimed (km/kg) | Typical Real-World City (km/kg) |
|---|---|---|
| Maruti WagonR CNG | 33.5 | 26–28 |
| Maruti Swift CNG | 32.5 | 25–27 |
| Tata Tiago CNG | 26.5 | 21–23 |
| Hyundai Aura CNG | 28.4 | 22–24 |
Note: Real-world figures are approximate ranges based on commonly reported owner experiences and may vary with driving style, AC use, and traffic conditions. Replace/expand this table with figures you can actually stand behind — even a small honest dataset outperforms none.
Frequently Asked Questions for CNG Calculator
Is CNG actually cheaper than petrol in 2026?
Yes, in almost every Indian city CNG remains significantly cheaper per kilometre than petrol, even after accounting for CNG’s slightly lower mileage compared to petrol in the same car. The exact savings depend on local CNG and petrol prices, which you can enter into the calculator above for a precise figure.
How long does it take to recover the cost of a CNG kit or factory-fitted CNG car?
This depends on your daily driving distance. Higher daily mileage drivers (cab drivers, long commuters) typically recover the added cost of a CNG variant within 12–18 months. Low-mileage drivers may take considerably longer, and should compare their expected annual savings using the calculator before deciding.
Does CNG reduce a car’s performance or engine life?
Modern factory-fitted CNG systems are engineered by manufacturers to minimize performance loss, though a mild reduction in power output compared to petrol mode is common. Well-maintained CNG engines generally do not have a shorter lifespan than petrol-only engines.
Why is my real-world mileage lower than the number shown here?
The default mileage figures come from ARAI certified testing, which is done under controlled lab conditions. City traffic, AC usage, and driving style typically bring real-world mileage down by 15–25%. You can manually adjust the mileage field in the calculator to match your own car’s actual performance.