Miles Per kWh Calculator

You'll often hear owners of electric vehicles (EVs) refer to the term miles per kWh (mi/kWh) when discussing their vehicle's energy efficiency, but what does it actually mean? While the fuel efficiency of petrol vehicles is commonly measured in miles per gallon (MPG), we obviously need a different unit of measurement for EVs. That's where miles per kWh comes in.

What is miles per kWh?

The miles per kWh measurement shows how many miles an EV can travel using one kilowatt-hour (kWh) of electricity. When assessing an EV's running costs, looking at its mi/kWh can help you compare its energy efficiency to other electric vehicles (and, with a little math, to gas vehicles too).

On average, most EVs achieve around 3 to 5 miles per kWh. However, less efficient models may only get around 2.5 miles per kWh, while high-efficiency models can reach up to 6 miles per kWh or more. ⚡

How is miles per kWh calculated?

The process for calculating miles per kWh is fairly straightforward — you divide the miles driven by the electricity used (in kWh). I'll give a simple example. If your EV covers 50 miles using 10 kWh, it achieves 5 miles per kWh (50 divided by 10).

Why is miles per kWh important?

There are several reasons why mi/kWh can be an important metric:

• Efficiency Insight: It measures an EV's energy use directly.
• Cost Savings: Higher miles per kWh can mean lower electricity costs (depending on the cost of electricity at time of charge).
• Environmental Impact: Greater efficiency typically means less energy being used and, therefore, lower emissions.

For more details about EV efficiency, see our references section below.

Factors that affect miles per kWh

As with the MPG measurement for gas-powered vehicles, there are a number of factors that can affect an EV's efficiency you should be aware of:

• Driving habits: Aggressive acceleration and high speeds tend to reduce efficiency.
• Terrain: Hilly or mountainous terrain tends to consume more energy than flat terrain, leading to fewer miles per kWh.
• Temperature: Extreme temperatures (both hot and cold) can reduce battery efficiency. Heating and cooling the cabin uses electrical energy that would otherwise be used for driving.
• Accessories: Using air conditioning, heated seats and other accessories will use electrical energy and reduce your EV's efficiency.

So, we've learned that adjusting your driving habits can help you maximize your EV's efficiency and increase the range. MyEV has an article with ten tips for maximizing your EV's range, which you can find here.

Other frequently asked questions

Here are some answers to other questions about miles per kWh:

How does miles per kWh relate to my electricity bill?

The miles per kWh figure provides a snapshot of your EV's efficiency. To then estimate the overall electricity cost for running your vehicle, simply multiply the kWh used to your electricity cost per kWh.

Is a higher miles per kWh always better?

Generally, yes. A higher miles per kWh figure means your EV uses less electricity to travel the same distance, which would potentially lower your energy bill. However, there are obviously additional factors to consider when deciding which EV to buy. Things like the purchase cost of the vehicle, insurance, and maintenance.

How does miles per kWh compare to MPGe?

While miles per kWh measures distance per kilowatt-hour, MPGe translates this to a gasoline equivalent (we have a MPGe calculator here, by the way). Both metrics are useful but offer different perspectives on efficiency.

Summary

I hope this article has helped you understand a little more about the miles per kWh measurement, and the factors that affect how many miles of charge you might get from your battery. It's worth remembering that ongoing research and technological advances will continue to influence these metrics. So, as battery technology improves, the efficiency of EVs should also increase.

Should you have any feedback, suggestions or questions about this calculator and article, please get in touch.

References