EV efficiency converter
EV efficiency is quoted in different ways: miles per kWh (like mpg, higher is better), or Wh per mile and kWh per 100 km (like litres per 100 km, lower is better). This converter switches between all six.
| Miles per kWh | 4 mi/kWh |
| Kilometres per kWh | 6.437 km/kWh |
| Wh per mile | 250 Wh/mile |
| Wh per km | 155.343 Wh/km |
| kWh per 100 miles | 25 kWh/100 mi |
| kWh per 100 km | 15.534 kWh/100 km |
How it works
Wh/mile = 1000 / (miles per kWh); kWh/100 miles = 100 / (miles per kWh); km/kWh = miles per kWh x 1.609344
Every unit converts through miles per kWh. Distance-per-energy units (mi/kWh, km/kWh) are divided into 1000 or 100 to give energy-per-distance units (Wh/mile, kWh/100 miles), and miles become kilometres by multiplying by the exact 1.609344.
Worked example
4 mi/kWh expressed in every unit:
| Miles per kWh | 4 mi/kWh |
| Kilometres per kWh | 6.437 km/kWh |
| Wh per mile | 250 Wh/mile |
| Wh per km | 155.343 Wh/km |
| kWh per 100 miles | 25 kWh/100 mi |
| kWh per 100 km | 15.534 kWh/100 km |
Frequently asked questions
What is a good miles per kWh?
Roughly 4 miles per kWh or better is efficient for an electric car, 3 to 4 is typical, and under 3 is common for large vehicles or fast motorway driving.
Why do some countries use kWh per 100 km?
Europe quotes consumption as energy per distance, like litres per 100 km for petrol. The UK often uses miles per kWh, like mpg, where a bigger number is better.
Is a higher or lower number better?
For miles per kWh and km per kWh, higher is better. For Wh per mile, kWh per 100 miles, Wh per km and kWh per 100 km, lower is better.
How do I convert miles per kWh to kWh per 100 km?
Divide 100 by (miles per kWh x 1.609344). For example, 4 miles per kWh is 100 / 6.437376 = 15.53 kWh per 100 km.