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What is a Fuel Cost Per KM Calculator?
Fuel Cost Per KM — Quick Reference
| Vehicle Type | Fuel | Typical Mileage | Cost per KM |
|---|---|---|---|
| Small car (Maruti, Tata) | Petrol | 18-22 km/L | ₹4.50-5.50/km |
| Mid-size car | Petrol | 14-18 km/L | ₹5.50-7.00/km |
| SUV/Diesel | Diesel | 14-18 km/L | ₹5.00-6.50/km |
| CNG Car | CNG | 22-28 km/kg | ₹3.00-4.20/km |
| Bike/Scooter | Petrol | 40-60 km/L | ₹1.75-2.60/km |
| Electric car | Electricity | 6-8 km/unit | ₹1.50-2.00/km |
Monthly Fuel Cost by Usage
| Daily Driving | Monthly KMs | Petrol (₹6/km) | CNG (₹3.5/km) | Savings with CNG |
|---|---|---|---|---|
| 10 km/day | 300 km | ₹1,800 | ₹1,050 | ₹750/month |
| 20 km/day | 600 km | ₹3,600 | ₹2,100 | ₹1,500/month |
| 30 km/day | 900 km | ₹5,400 | ₹3,150 | ₹2,250/month |
| 50 km/day | 1,500 km | ₹9,000 | ₹5,250 | ₹3,750/month |
How is Fuel Cost Per KM Calculated?
The formula is straightforward:
To calculate monthly fuel cost:
Factors that affect real-world mileage:
- Driving conditions: City traffic vs. highway — highway gives 20–30% better mileage.
- Vehicle age and maintenance: Worn spark plugs, dirty air filters, and low tyre pressure all reduce efficiency.
- Air conditioning: Running AC increases fuel consumption by 8–15%.
- Driving speed: Most petrol cars achieve peak efficiency between 60–80 km/h.
Example Calculation
Tip: Always use real-world mileage (70–80% of ARAI figures) for accurate estimates.
Frequently Asked Questions
For a typical petrol car with 18 km/L mileage and ₹102/L fuel price, cost per km is ₹5.67. For 15 km/L mileage: ₹6.80/km. Higher mileage and lower fuel price = lower running cost.
CNG cost per km is typically ₹3.00-4.20 depending on CNG price and vehicle mileage. At ₹90/kg and 25 km/kg: ₹3.60/km — about 40% cheaper than petrol cars. Annual savings for 15,000 km: ₹25,000-40,000.
Usually yes — diesel is ₹8-10/L cheaper and diesel engines give better mileage (15-20 km/L vs 14-17 for petrol). However, diesel cars cost ₹1-2 lakh more upfront. Break-even is typically 70,000-90,000 km.
Fuel cost = (Distance ÷ Mileage) × Fuel price. Example: 500 km trip in car with 18 km/L mileage at ₹102/L: (500 ÷ 18) × 102 = ₹2,833.
Yes — AC reduces fuel efficiency by 10-15% in city driving and 5-8% on highways. For a car giving 18 km/L without AC, expect 15-16 km/L with AC on in city conditions.
Related Calculators
Disclaimer: Results are for informational and educational purposes only — not financial, tax, or legal advice. Tax slabs, rates (EPF, PPF, home loan), and rules shown are based on data available in 2025 and may change. Always verify with a qualified professional or official government sources before making financial decisions.