What Is Miles Per kWh?
Miles per kWh (mi/kWh) is the standard measure of electric vehicle efficiency, much like miles per gallon (MPG) is for gasoline cars. It tells you how far your EV travels on one kilowatt-hour of electricity. A higher number means a more efficient vehicle that costs less to drive. Most modern EVs achieve between 3 and 5 miles per kWh depending on the model, driving style, weather, and terrain.
How to Use This Calculator
Enter the total miles you drove for a trip or charging cycle, then enter the energy your car consumed in kilowatt-hours (kWh). You can find kWh used from your charger's display, your car's trip computer, or by checking how many kWh you added at a charging session. Click calculate to see your efficiency in miles per kWh, along with two helpful conversions: kWh per 100 miles and watt-hours (Wh) per mile.
The Formula Explained
The core calculation is simple: $$\text{Miles per kWh} = \frac{\text{Miles Driven}}{\text{Energy Used (kWh)}}$$ To get watt-hours per mile, the calculator multiplies kWh by 1,000 and divides by miles. The kWh per 100 miles figure divides energy by distance and scales it to a 100-mile basis — a common rating used on US window stickers.
Worked Example
Suppose you drove 250 miles and used 62.5 kWh of electricity. Your efficiency is $$250 \div 62.5 = 4 \text{ miles per kWh}$$ That equals 25 kWh per 100 miles, or 250 Wh per mile. If electricity costs $0.15 per kWh, that 250-mile trip costs about $9.38 in energy.
FAQ
What is a good miles-per-kWh figure? Around 4 mi/kWh is very good; efficient EVs in mild weather can exceed 4.5, while larger trucks and SUVs may sit closer to 2–3.
Why is my efficiency lower in winter? Cold temperatures reduce battery performance and cabin heating draws extra power, both lowering miles per kWh.
How do I convert to kWh per 100 miles? Divide 100 by your miles-per-kWh figure — for example, \(4 \text{ mi/kWh}\) equals 25 kWh per 100 miles.
