EV Electricity Charging Cost Calculator
This EV electricity charging cost calculator figures out what it actually costs to charge your car at home, including the electricity lost as heat during charging that never reaches the battery. Use your own electricity rate and either a direct kWh figure or your battery's capacity and charge percentage.
Default 12% is a reasonable middle estimate for Level 2 home charging; adjust if you have a more specific figure for your vehicle.
Cost to charge
Enter your rate and charging details to see your cost.
How this calculator works
kWh drawn from the wall = kWh added to the battery ÷ (1 − loss%). That wall-drawn figure, not the battery figure, is what your electricity rate actually applies to, since that's what your meter measures. Cost = kWh from the wall × your rate.
This calculator applies a charging-loss percentage to the kWh you want added to your battery, since a home charger always draws somewhat more electricity from the wall than actually reaches the battery. The default 12% loss figure sits between the specific loss rates independent testing has measured for Level 2 home charging — InsideEVs reported 14% loss on a Tesla Model Y Performance and 9.7% on a Renault Zoe using a Level 2 wall box. Actual loss varies by vehicle, charger, and temperature, so adjust the field if you have a more specific figure for your own setup. Last checked September 2026.
Frequently asked questions
Why does charging cost more than just battery kWh × rate?
Some electricity is lost as heat in the charging process, both in the charger itself and the car's onboard charging system, so the wall draws more electricity than actually ends up stored in the battery. Independent testing summarized by InsideEVs found real-world Level 2 losses in the roughly 10-15% range for the vehicles tested.
Is Level 2 home charging more efficient than a standard wall outlet (Level 1)?
Yes, generally by a wide margin. The same InsideEVs testing found a Renault Zoe lost 24.2% charging from a standard household outlet (Level 1) versus 9.7% on a Level 2 wall box — more than double the loss on the slower, unshielded connection.
How many watts does a Level 2 home EV charger use?
A typical Level 2 home charger draws around 7,200 watts (7.2 kW), according to EnergySage, running on a 240-volt circuit at 32 to 40 amps. That's roughly five times the draw of a standard 120-volt wall outlet.
How can I reduce my EV charging cost?
Charge during off-peak hours if your utility offers time-of-use pricing, since overnight rates are often lower. Keeping the battery in a moderate charge range day-to-day (rather than always charging to 100%) and charging in a garage or otherwise temperature-moderated space can also improve real-world efficiency, since charging losses tend to increase in very cold weather.
Related tools
This calculator provides estimates based on the figures you enter and a general charging-loss assumption. Actual cost depends on your specific vehicle, charger, ambient temperature, and electricity rate structure.