Km/kWh is simply how many kilometres an electric vehicle travels using one kilowatt-hour (kWh) of battery energy. It’s the EV equivalent of fuel economy. A higher km/kWh means the car squeezes more distance out of every unit it draws from the pack, so you spend less per kilometre and get more usable range.
Key takeaways
- Km/kWh measures distance per unit of energy, so it’s the honest efficiency number because it doesn’t change with battery size.
- Higher km/kWh = lower cost per km and more range from the same pack.
- Estimate range with a simple formula: battery kWh x km/kWh.
- The Tata Tiago EV returns roughly 7.8 km/kWh in real-world testing.
- The MG Windsor EV manages about 8.1 km/kWh , among the better figures for an Indian EV.
- Your cost per km is just your electricity tariff divided by km/kWh.
What does km/kWh actually mean?
It tells you efficiency, not range. Think of kWh as the “litres” in the tank and km/kWh as the “kilometres per litre.” A car rated at 8 km/kWh travels 8 km for every kilowatt-hour it pulls from the battery. Because the figure is per unit of energy, it lets you compare a small hatchback against a big SUV fairly, even when their battery sizes are wildly different.
Why is km/kWh better than just looking at range?
Because range hides the battery size. A car can claim 500 km of range simply by carrying a huge, heavy, expensive pack while being inefficient. Km/kWh strips that out and shows how well the car uses the energy it has. Two EVs can both do 350 km, but the one doing it on a smaller pack has the higher km/kWh, which means cheaper running costs and faster charging.
How do I estimate range from km/kWh?
Multiply the usable battery size by the efficiency.
Range = battery kWh x km/kWh
So a 24 kWh pack at 8 km/kWh gives roughly 24 x 8 = 192 km of real-world range. This is a quick back-of-the-envelope estimate and assumes mixed driving; highway speeds, AC use, and hills will pull the number down.
How do I work out cost per km?
Divide your electricity tariff by the efficiency.
Cost per km = electricity tariff (per kWh) / km per kWh
If you pay Rs 8 per kWh at home and your EV does 8 km/kWh, that’s 8 / 8 = Rs 1 per km. The same car on a fast charger at Rs 20 per kWh costs 20 / 8 = Rs 2.50 per km. Efficiency is the multiplier that decides how much the tariff actually hurts.
Worked example
Here’s how a few real numbers play out at a home tariff of Rs 8 per kWh.
| Model | Real-world efficiency | Range from a 25 kWh pack | Cost per km @ Rs 8/kWh |
|---|---|---|---|
| Tata Tiago EV | ~7.8 km/kWh | ~195 km | ~Rs 1.03 |
| MG Windsor EV | ~8.1 km/kWh | ~203 km | ~Rs 0.99 |
The gap looks small per kilometre, but over 15,000 km a year it adds up, and the more efficient car also recovers range faster on a charge.
Frequently asked questions
What’s a good km/kWh figure for an Indian EV?
Anything around 7 to 8.5 km/kWh in mixed real-world driving is solid for a city EV. Lighter hatchbacks tend to sit at the higher end, while heavier SUVs land lower because they carry more mass.
Does km/kWh change with how I drive?
Yes. Hard acceleration, sustained highway speeds, air conditioning, and hilly terrain all lower your km/kWh. Smooth driving and using regenerative braking in traffic push it back up.
Is the company-claimed efficiency the same as real-world?
Usually no. Lab-claimed figures run optimistic, which is why independent road tests matter. See our real-world range vs ARAI claimed range benchmark for how big that gap gets.
How do I compare two EVs fairly using this?
Look at km/kWh first, then battery size. The efficiency tells you running cost, and multiplying by the pack tells you range. Our EV cost per km India benchmark puts these side by side, and you can check charging math with the battery charging time calculator .
Sources
Last updated: 23 June 2026.
