Miles per kWh definition
With a traditional car, the MPG number tells you how many miles the car will go on 1 gallon of petrol or diesel.
In an electric car, the miles per kWh figure tells you how many miles the car will go on 1 kWh, or unit, of electricity.
So if your EV has a battery size of 50 kWh and an efficiency rating of 3 miles per kWh, then on average it can travel 150 miles on a fully charged battery (50 kWh x 3 miles per kWh).
What if the miles per kWh figure is not displayed? Just take the battery range of the car and divide by the battery size. So an EV with a 240 mile range and a battery capacity of 60 kWh would have an efficiency rating of 4 miles per kWh (240 ÷ 60).