Petrol vs EV Calculator
Compare the running cost of a petrol car against an electric vehicle and see your savings per trip and per km.
Formula last reviewed 4 August 2026 · How we verify our calculators
You save with EV
- Petrol cost
- ₹667
- EV cost
- ₹120
- Petrol cost/km
- ₹7
- EV cost/km
- ₹1
Updates live as you type
Frequently asked questions
Energy used = (distance ÷ 100) × efficiency in kWh/100km, multiplied by your electricity price. For 100 km at 15 kWh/100km and ₹8/kWh, that is ₹120.
On energy cost almost always, because electricity per km is far cheaper than petrol. This tool compares running cost only — not the purchase price, battery replacement or maintenance.
Most compact EVs use roughly 12–18 kWh per 100 km. Check your model’s rated consumption, and remember home charging is far cheaper than public fast charging.
No. EVs often cost more to buy, so factor in that premium separately and divide it across your expected kilometres to judge total cost of ownership.
One-twenty against six-sixty-seven
Driving 100 km in a petrol car returning 15 km/L with fuel at ₹100 costs ₹666.67. The same 100 km in an EV consuming 15 kWh at ₹8 per unit costs ₹120. The saving is ₹546.67 — running cost of ₹1.20 per km against ₹6.67.
That is a genuine and large difference, and it is also only one line of the comparison. The running cost strongly favours the EV; the purchase price does not. Whether an EV is cheaper overall depends entirely on how many kilometres you drive before the running-cost saving repays the price premium.
The calculations
Petrol cost = (distance ÷ mileage) × price per litre 100 ÷ 15 = 6.67 litres × ₹100 = ₹666.67
EV cost = (distance ÷ 100) × kWh per 100 km × electricity price 1 × 15 × ₹8 = ₹120
Saving = petrol cost − EV cost
The break-even that actually decides it
The comparable EV of a given petrol car typically costs ₹3–₹8 lakh more up front. At a saving of ₹5.47 per kilometre:
- A ₹4,00,000 premium repays at about 73,000 km
- A ₹6,00,000 premium at about 110,000 km
Against typical Indian usage of 10,000–15,000 km a year, that is five to eleven years of driving. For a high-usage driver — a commercial vehicle, a long daily commute, 25,000 km a year — the same premium repays in three to four years and the EV is clearly the better economic choice. For someone driving 8,000 km a year, it usually is not, at least on running cost alone.
What changes the answer
Where you charge. Home charging at domestic tariffs of ₹6–₹10 per unit is what produces the ₹1.20/km figure. Public DC fast chargers commonly charge ₹18–₹25 per unit, which takes the running cost to ₹2.70–₹3.75 per km — still well under petrol, but roughly three times the home figure. An EV without reliable home charging is a substantially different financial proposition.
Charging losses. Roughly 10–15% of the energy drawn from the wall does not reach the battery. A true cost per km is a little above the simple calculation here.
Battery degradation. Modern packs typically retain 80% or more of capacity after eight years, and most manufacturers warrant to that level. Out-of-warranty replacement remains expensive, though prices have fallen sharply.
Maintenance. An EV has no oil changes, no filters, no clutch, no exhaust and far less brake wear thanks to regeneration. Servicing typically runs 40–60% lower than an equivalent petrol car — a saving this calculator does not include.
Purchase incentives. Reduced GST on EVs, lower road tax in several states and state-level subsidies all narrow the price gap, and they change frequently.
Reading the result
The figures are running cost only. A complete comparison needs the price premium, maintenance, insurance (often slightly higher on EVs due to battery value), resale value (still less certain for EVs) and any incentives.
The honest summary: EVs win decisively on cost per kilometre, and win overall for high-usage drivers with home charging. For low-usage drivers dependent on public charging, the economics are considerably tighter than the per-kilometre figure suggests.
Common mistakes
Using home tariffs while planning to charge publicly. A threefold difference in running cost.
Ignoring the purchase premium. It is the whole of the break-even calculation.
Omitting charging losses. Add roughly 10–15% to the EV figure.
Forgetting maintenance savings. These favour the EV and are frequently left out.
Assuming the running-cost gap is permanent. Electricity tariffs and fuel prices both move, and EV-specific tariffs are still evolving.