Skip to content
Utilboxes

EV Charging Cost Calculator

Enter your battery size, start and end charge and electricity price to see what one charge costs, or your car's consumption and distance for the cost per mile or kilometre and per month, compared with petrol. Charging a 60 kWh battery from 20% to 80% at $0.15 per kWh costs about $6, allowing for charging losses.

Runs entirely in your browser

Updated

How to use the EV Charging Cost Calculator

  1. 1Choose One charge or Cost per distance.
  2. 2For one charge, enter the battery size, the start and end charge levels and your electricity price.
  3. 3For running costs, enter your car's consumption, the distance you drive and how much charging is done in public.
  4. 4Add a petrol car's fuel economy and fuel price to compare.

How it works

The energy a charge adds is the battery capacity multiplied by the change in charge level: taking a 60 kWh battery from 20% to 80% adds 36 kWh. Charging is not perfectly efficient — some energy is lost as heat in the charger and battery — so more is drawn from the grid than ends up in the battery. Home charging typically loses around 10%, which is the default efficiency here.

Running cost per mile or kilometre comes from the car's consumption — shown on its dashboard or in its specification as kWh per 100 km, kWh per 100 miles or miles per kWh. Divided by charging efficiency and multiplied by your electricity price, it gives the cost of each mile or kilometre. Public rapid chargers usually cost several times more per kWh than home electricity, so the share of public charging matters.

The petrol comparison converts fuel economy into fuel used per mile or kilometre and multiplies by the fuel price, using exact gallon sizes: a US gallon is 3.785 litres and a UK gallon 4.546 litres, which is why UK mpg figures look higher for the same car.

The formula

cost per charge = battery × (end % − start %) ÷ efficiency × price per kWh
battery
usable battery capacity in kWh
efficiency
the share of grid electricity that reaches the battery

Running cost per distance = consumption ÷ efficiency × electricity price.

Worked example

Charging a 60 kWh battery from 20% to 80% at $0.15 per kWh

  1. Energy added: 60 kWh × (80% − 20%) = 36 kWh.
  2. Drawn from the grid at 90% efficiency: 36 ÷ 0.9 = 40 kWh.
  3. 40 kWh × $0.15.

Result: $6.00 for the charge.

Tips and common mistakes

  • Use the consumption shown on your car's dashboard over a few weeks; it reflects your real driving better than the official figure.
  • Set the share of public charging honestly; rapid chargers can cost several times more per kWh than home electricity.
  • If your tariff is cheaper overnight, enter the overnight price for home charging.
  • Expect higher consumption in winter, when heating and cold batteries use more energy.

Frequently asked questions

How much does it cost to fully charge an electric car?
Divide the battery size by the charging efficiency and multiply by your electricity price. A 60 kWh battery at $0.15 per kWh costs about $10.00 from empty to full at home.
Is it cheaper to charge at home?
Almost always. Home electricity — especially on an off-peak tariff — usually costs far less per kWh than public rapid charging.
Why does my car use more energy in winter?
Cold batteries are less efficient and heating the cabin draws power, so consumption rises in cold weather. Use a winter figure from your car's trip computer for a realistic estimate.
Should I charge to 100%?
Many manufacturers recommend charging to around 80% for everyday use and to 100% before long trips. Check your car's handbook, as advice differs between battery types.
How do I convert miles per kWh to kWh per 100 miles?
Divide 100 by the miles per kWh. A car that does 3.5 miles per kWh uses about 28.6 kWh per 100 miles.
What is charging efficiency?
The share of electricity from the grid that ends up in the battery. Some is lost as heat; around 90% is typical for home charging, which is the default here.
Why do UK and US mpg figures differ for the same car?
The gallons are different sizes. A UK gallon is 4.546 litres and a US gallon 3.785, so the same car shows a higher mpg in UK figures.
Share this toolShare on XShare on FacebookShare on LinkedInShare on RedditShare by email

Guides

Related tools

Engine CC to HP ConverterConvert cc to litres and cubic inches, and estimate horsepower from engine size.ConvertersSpeed Converterkm/h, mph, knots, m/s and the speed of sound.ConvertersPercentage CalculatorWork out percentages, increases, decreases and 'what percent of'.Subscription Cost TrackerList your subscriptions to see the real monthly and yearly cost, then print it.