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About the EV charging cost calculator
How much does it cost to charge an electric car? It depends on three things: how many kWh go into the battery, the price per kWh, and the energy lost while charging. This free EV charging cost calculator puts them together.
Type the battery size, the charge level you start from and charge to, and the price per kWh at home and at a public charger. You get the cost of one charge in both places, the kWh it takes and the range it adds.
Add the car's efficiency (mi/kWh, kWh/100 mi, kWh/100 km or km/kWh) to see the cost per mile or km. Type a gas car's fuel economy and fuel price to compare, and the miles you drive in a month to see what you save per month and per year.
The prices in the boxes are examples only. Nothing is looked up — type the price on your electricity bill and at the chargers you use.
Features
- Cost of one charge — at home and at a public charger, from any level to any level
- kWh from the grid — the energy into the battery plus the charging loss you set
- Range added — in miles or km, from your car's efficiency
- Cost per mile or km — at home, in public and for a gas car
- Four efficiency units — mi/kWh, kWh/100 mi, kWh/100 km or km/kWh; the number converts when you switch
- Monthly and yearly saving — with your mileage and the share you charge at home
- Any currency — your numbers are saved only on this device
Worked example
The page opens with a 75 kWh battery charged from 20% to 80%, a 10% charging loss, a car that goes 3.5 miles per kWh, $0.17 per kWh at home and $0.45 at a public fast charger:
- Into the battery: 75 × (80% − 20%) = 45 kWh
- From the grid: 45 ÷ 0.9 = 50 kWh
- One charge at home: 50 × $0.17 = $8.50; at a public charger: 50 × $0.45 = $22.50
- Range added: 45 × 3.5 = about 158 miles
- Per mile: $0.054 at home, $0.143 in public
A gas car with 28 mpg and gas at $3.50 a gallon costs 3.50 ÷ 28 = $0.125 a mile. For 1,000 miles a month, charging at home 80% of the time, the electric car costs about $72 a month and the gas car $125 — a saving of about $53 a month, or $639 a year.
What one charge costs
At $0.17 per kWh at home and $0.45 at a public charger, with a 10% charging loss:
| Battery | 20% → 80%, home | 20% → 80%, public | 0% → 100%, home | 0% → 100%, public |
|---|---|---|---|---|
| 40 kWh | $4.53 | $12.00 | $7.56 | $20.00 |
| 60 kWh | $6.80 | $18.00 | $11.33 | $30.00 |
| 75 kWh | $8.50 | $22.50 | $14.17 | $37.50 |
| 100 kWh | $11.33 | $30.00 | $18.89 | $50.00 |
Cost per 100 miles
For a car that goes 3.5 miles per kWh, with a 10% charging loss:
| Price per kWh | Cost per 100 miles |
|---|---|
| $0.10 | $3.17 |
| $0.15 | $4.76 |
| $0.17 | $5.40 |
| $0.25 | $7.94 |
| $0.35 | $11.11 |
| $0.45 | $14.29 |
| $0.55 | $17.46 |
And for gas cars at $3.50 a gallon: 20 mpg costs $17.50 per 100 miles, 25 mpg $14.00, 28 mpg $12.50, 30 mpg $11.67 and 40 mpg $8.75. Charging at home is usually far cheaper than gas. Fast charging in public can cost as much as gas, or more.
Charging loss
Not every kWh that passes the meter ends up in the battery. Some is lost as heat in the charger, the cables and the battery. With a home wall charger, about 10% is a common figure; on a normal wall socket it can be more. You pay for what the meter counts, so the calculator divides the battery energy by (1 − loss). Set the loss you want — 0% if you only want the battery energy.
Frequently asked questions
How much does it cost to charge an electric car?
Multiply the kWh you add by the price per kWh, and add the charging loss. A 75 kWh battery from 20% to 80% takes about 50 kWh from the grid: $8.50 at $0.17 per kWh, or $22.50 at a $0.45 public charger.
How do I work out the cost per mile?
Divide the price per kWh by the miles per kWh, then add the loss: $0.17 ÷ 3.5 ÷ 0.9 = $0.054 a mile. In kWh/100 km: 17 kWh/100 km at €0.30 with 10% loss is 17 × 0.30 ÷ 0.9 = €5.67 per 100 km.
Why charge only to 80%?
Many drivers charge to about 80% for daily use, and fast charging slows down a lot above 80%. Charge to 100% before a long trip if your car's maker says so. You can set any levels here.
Is it cheaper than gas?
At home it usually is. At $0.17 per kWh, a car with 3.5 mi/kWh costs $5.40 per 100 miles against $12.50 for a 28 mpg car with gas at $3.50. Fast chargers cost more; type your own prices to compare.
What about time-of-use or night rates?
Type the price you pay at the time you charge. If you charge at night on a cheaper rate, use that price for Home.
Does it include the cost of the charger or the car?
No. It counts only the electricity. For the monthly cost of a car itself, see the Car Lease Calculator or the Auto Loan Calculator.
Related tools
- Electricity Cost Calculator — what each device in your home costs to run
- Fuel Cost Calculator — the fuel cost of a trip in a gas car
- Fuel Economy Converter — mpg, L/100 km and km/L
- Solar Panel Calculator — make your own electricity
- Car Lease Calculator — the monthly cost of leasing a car
How to use it
- Type the battery size in kWh, or tap a button, and the charging loss
- Type the level to charge from and charge to, in %
- Type the price per kWh at home and at a public charger
- Type the car's efficiency and choose its unit
- Under Compare with a gas car, type the fuel economy and the fuel price
- Open More options for the distance you drive per month and the share charged at home
- Read the cost of one charge, the cost per mile or km, and the monthly saving
