The fairest way to compare petrol and electric running costs is cost per kilometre. Here is how to calculate it with your own numbers.
Petrol: cost per km
Petrol price per litre ÷ kilometres per litre = cost per km.
Example: if petrol costs ₹105 per litre and your car does 15 km per litre, that is ₹105 ÷ 15 = ₹7.00 per km.
Electric: cost per km
Price per kWh ÷ kilometres per kWh = cost per km.
Many electric cars cover roughly 6–8 km per kWh in mixed driving. Example with 7 km per kWh:
- Home charging at ₹8 per kWh: ₹8 ÷ 7 = about ₹1.15 per km.
- Public AC charging at ₹15 per kWh: about ₹2.15 per km.
- Public DC fast charging at ₹22 per kWh: about ₹3.15 per km.
These prices are examples only. Use your actual electricity tariff, the price shown at the charger and your car's real efficiency.
What the example shows
Even with public fast charging, the electric cost per kilometre in this example is less than half the petrol cost. With home charging, it is a fraction of it.
What changes the numbers
- Driving style and speed: highway speeds use more energy.
- Air conditioning and load.
- Charging losses: a small amount of energy is lost during charging, especially on AC.
- Your mix of home and public charging.
Beyond energy
Electric cars also tend to cost less to maintain, with no oil changes and less brake wear. That adds to the running-cost difference over time.