EV Charging Cost vs Gas Calculator

Compare the cost per mile and per year of charging an EV versus filling up a gas car.

12,000 by default. Greater than 0, up to 200,000 miles.

0.30 kWh per mile is the example. Up to 2 kWh per mile, or 10 miles per kWh. Switching keeps the number you typed.

$ per kWh. $0.17 is an example. Up to $10.

$ per kWh. $0.48 is an example for public DC fast charging. Up to $10. Leave blank only when home charging share is 100%.

Percent. The 90% default applies to all charging, at home and in public. Greater than 0, up to 100%.

Percent of charging done at home. 100% by default. The rest uses the public price. Up to 100%.

$ per gallon. $3.20 is an example. Up to $20.

The comparison car. Greater than 0, up to 150 miles per gallon.

Results update as you type.

Results

Enter your numbers to see the results.

Enter your annual miles, the EV's efficiency, your electricity price and the gas car's MPG to compare cost per mile and per year side by side. It counts the energy lost while charging and shows the electricity price where the EV stops saving you money. EVs usually cost less to fuel, but not always.

How to use it

  1. Enter the miles you drive in a year (12,000 by default).
  2. Enter the EV's efficiency in kWh per mile, or in miles per kWh if that's what your car shows. 0.30 kWh/mi is the same as 3.33 mi/kWh.
  3. Enter your electricity price. The defaults are examples only: $0.17 per kWh for home charging and $0.48 for public DC fast charging. Use your utility bill and the prices at chargers you actually use.
  4. Set charging efficiency. The default is 90%, since some energy is lost as heat, and it applies to all your charging, at home and in public.
  5. Enter the gas price and the comparison car's MPG.
  6. Optional: set how much of your charging happens at home, like 80% at home and 20% on road trips. The tool uses a weighted average of your home and public prices.

Where to find your numbers

How it works

The EV's yearly cost is the electricity it draws from the grid, including charging losses, times your weighted average price for home and public charging. Gas cost per mile is the gas price divided by MPG.

Worked examples

Home charging vs. a 30 MPG car.

12,000 miles, 0.30 kWh/mi, $0.17 per kWh at 90% efficiency, against gas at $3.20 and 30 MPG. The EV costs $0.0567 a mile, or $680 a year, drawing 4,000 kWh from the grid. The gas car costs $0.1067 a mile, or $1,280. You'd save $600 a year. The EV keeps winning until home electricity reaches about $0.32 per kWh.

Cheap power vs. a thirsty car.

15,000 miles in an efficient EV (0.25 kWh/mi) on $0.13 power at 85% charging efficiency costs $573.53 a year. A 25 MPG car at $3.50 a gallon costs $2,100. Savings: $1,526.47 a year.

Fast charging only vs. an efficient gas car.

10,000 miles at 0.33 kWh/mi with 90% charging efficiency draws 3,666.67 kWh. All on public DC fast chargers at $0.48 per kWh, that's $1,760 a year. A 35 MPG car at $3.00 costs $857.14. Here the EV costs $902.86 more. To beat that gas car, fast charging would need to cost less than about 23.3¢ per kWh.

Mostly home, some road trips.

Same driving as the first example (12,000 miles, 0.30 kWh/mi, 90%), but 80% of charging at home for $0.17 and 20% at fast chargers for $0.48. The blended price is 0.8 × $0.17 + 0.2 × $0.48 = $0.232 per kWh. On 4,000 kWh from the grid, the EV costs $928 a year ($0.0773 a mile) against $1,280 for gas, so you'd save $352, about $248 less than charging only at home.

The takeaway: home charging is where most of the savings come from. If you can't charge at home, run the numbers with the prices at chargers near you before assuming you'll save.

FAQ

Is it cheaper to charge an EV than to buy gas?

Usually, when you charge at home. In the first example the EV costs $680 a year against $1,280 for gas. With only public fast charging at $0.48 per kWh, it can cost more than an efficient gas car.

How much does it cost to charge an electric car?

Multiply the kWh you put in by your price per kWh. Driving 12,000 miles at 0.30 kWh per mile with 90% charging efficiency takes about 4,000 kWh, or $680 at $0.17.

What is EV cost per mile?

kWh per mile × price per kWh ÷ charging efficiency. At 0.30 kWh/mi and $0.17 with 90% efficiency, it's about 5.7¢ a mile.

How much does it cost to charge a Tesla?

The same math applies to any EV. Enter your model's efficiency from its trip screen or app, along with your home or Supercharger price.

Why does charging efficiency matter?

Some energy is lost as heat while charging, so your meter records more kWh than ends up in the battery. At 90% efficiency, 1,000 kWh in the battery takes about 1,111 kWh from the wall.

At what electricity price does an EV stop saving money?

Gas cost per mile × charging efficiency ÷ kWh per mile. Against a 30 MPG car with gas at $3.20, a 0.30 kWh/mi EV charging at 90% breaks even at about $0.32 per kWh.

Does this include maintenance, insurance or purchase price?

No. It compares energy costs only. Those other costs can matter just as much when you choose a car.