In this article
The headline difference between an electric car and a petrol one is simple: the EV costs more to buy and less to run. Whether it saves you money depends on how far you drive, what your petrol and electricity cost, and how long you keep the car. A short calculation tells you roughly when the extra price is recovered.
How the calculation works
- 1Petrol cost1,000 ÷ 15 = 66.7 litres × ₹105 = **₹7,000**.
- 2Electricity cost1,000 ÷ 7 = 142.9 kWh × ₹8 = **₹1,143**.
- 3Monthly saving₹7,000 − ₹1,143 = **₹5,857**.
- 4Payback on the extra price₹4,00,000 ÷ (₹5,857 × 12) = **5.7 years**.
The tool also shows the yearly saving and the cost per km for both fuels.
Cost per km, side by side
- ₹105 a litre
- 15 km per litre
- A fuel price rise hits every km
- ₹8 per kWh
- 7 km per kWh
- About one sixth of the petrol cost
At these prices the EV costs 16% as much per kilometre. Petrol costs 6.1 times more.
Distance changes everything
The saving grows with every kilometre, but the extra purchase price does not change. So the more you drive, the faster it pays back. A car that only does a few trips a week may never recover the extra cost before you sell it.
| Distance per month | Petrol cost | EV cost | Saving per month | Payback on ₹4 lakh extra |
|---|---|---|---|---|
| 500 km | ₹3,500 | ₹571 | ₹2,929 | 11.4 years |
| 1,000 km | ₹7,000 | ₹1,143 | ₹5,857 | 5.7 years |
| 1,500 km | ₹10,500 | ₹1,714 | ₹8,786 | 3.8 years |
| 2,000 km | ₹14,000 | ₹2,286 | ₹11,714 | 2.8 years |
Same prices as the example. Doubling the distance halves the payback time.
At 500 km a month the extra price takes over eleven years to recover. At 2,000 km it takes under three.
Home charging against public charging
The example uses ₹8 per kWh, the kind of rate you might pay for electricity at home. Public fast chargers are often priced much higher. At ₹18 per kWh the same 1,000 km costs ₹2,571 instead of ₹1,143, which cuts the monthly saving to ₹4,429 and stretches the payback to 7.5 years.
Even at the higher public price the EV is cheaper to run than petrol here, but the payback is longer. Use your own mix of home and public charging for the best estimate.
What the calculation leaves out
- Insurance, tax and registration, which can differ between EV and petrol cars.
- Maintenance, usually lower for an EV, with no engine oil or exhaust, but tyres and brakes still wear.
- Battery warranty and replacement, and how the battery ages over the years you plan to keep the car.
- Resale value, which depends on the model and how the market treats used EVs.
- Subsidies or tax benefits, which vary by state and time and can reduce the extra price.
- Fuel price changes, in either direction, over the years you keep the car.
Doing the comparison properly
- Find your real monthly distance from the odometer or trip meter, not a guess.
- Use your real fuel and electricity prices, and the split between home and public charging.
- Enter the price gap between the two cars you are comparing, after any subsidy.
- Check the payback against how many years you plan to keep the car.
- Run a second case with higher charging costs or lower distance to see the downside.
Questions people ask
How do I calculate the running cost per km of a petrol car?
Divide the petrol price per litre by the mileage in km per litre. At 105 rupees a litre and 15 km per litre, the cost is 7 rupees per km.
How do I calculate the running cost per km of an electric car?
Divide the electricity price per kWh by the efficiency in km per kWh. At 8 rupees per kWh and 7 km per kWh, the cost is about 1.14 rupees per km.
How long does it take for an EV to pay back its extra price?
Divide the extra price by the yearly fuel saving. With an extra price of 4 lakh rupees and a saving of about 70,286 rupees a year, payback is around 5.7 years.
Does charging at a public station change the result?
Yes. Public fast chargers usually cost more per kWh than home electricity, so the saving is smaller and the payback longer. Enter a blended price if you use both.
Does the calculator include maintenance and insurance?
No. It compares fuel and electricity cost and the extra purchase price only. Add insurance, maintenance, battery and resale differences separately if you want a full cost of ownership.
What if I drive very few kilometres?
Then the saving is small and the extra price may never be recovered while you own the car. Try different distances in the EV vs Petrol Savings Calculator to see how sensitive the payback is.