How this calculator works (no black box)
Every result here comes from two simple multiplications, and you should be able to check both by hand.
The EV side. Your monthly distance times the vehicle's efficiency gives the energy needed — a scooter doing 780 km a month at 30 Wh/km consumes 23.4 units of electricity. The blended tariff mixes your home rate with the share of charging you do on paid public networks, because that distinction is the single biggest factor riders ignore. A scooter that charges 90 percent at home at ₹8 per unit costs about ₹210 a month; the same scooter charging mostly on public chargers at ₹22 can cost ₹600 or more.
The petrol side. Monthly distance divided by real-world mileage gives litres; litres times your city's pump price gives rupees. Notice we said real-world mileage — the figure on the showroom window assumes ideal conditions, just like an EV's claimed range. If your scooter actually returns 42 km per litre rather than 50, the honest comparison uses 42.
The five-year view. We hold your electricity tariff flat and raise petrol 5 percent a year — close to the long-run trend, though fuel prices can stagnate for years. Even with zero petrol inflation the per-kilometre gap is so large that the conclusion rarely changes.
What the numbers usually show
For most Indian commuters the pattern is remarkably consistent. Running an electric scooter costs ₹0.25–0.40 per km with home charging, against ₹2.00–2.60 per km for a petrol scooter at 2026 pump prices. That is a 5–8x difference, and it is the engine behind every other EV argument: the higher purchase price, the battery worry, the resale question — all of them are weighed against this monthly saving.
Electric cars tell the same story with bigger numbers. A mid-size EV sedan using 140 Wh/km costs about ₹0.9–1.4 per km on home charging; a comparable petrol sedan at 14 km per litre costs ₹7.50 per km. A driver covering 1,200 km a month saves roughly ₹7,000 every month, which is why many Indian families now run one petrol car for trips and one EV for the daily commute.
Three mistakes people make with this comparison
Using claimed efficiency. Brochure numbers are measured in laboratory conditions. If your scooter's claimed range is 120 km, assume 85–100 km in mixed city riding — that is 32–37 Wh/km, not the advertised 25.
Ignoring where you charge. The public-charging share field matters more than any other input. At 20 percent public charging the monthly saving barely moves; at 80 percent it can halve. Apartment dwellers without a socket should read the home charging guide first.
Forgetting your time. A public-charge session costs 30–60 minutes; home charging costs zero minutes because it happens while you sleep. Any honest comparison should value that difference, even if no calculator can price it perfectly.