EV Charging Cost Calculator Widget

Add an EV charging cost calculator to your website. Drivers enter the battery size, the charge level they start and finish at, the charging efficiency and their price per kWh, and see the energy drawn from the grid, the cost of the session and the cost per 100 km or miles.

Travel & Auto Calculator Runs in your browser Free · no ads

Customize your widget

Theme
Auto follows the visitor's light/dark setting.
Style
Attribution on your page
Optional and entirely your choice. The exact line is shown in the code below; it links to the tool with rel="nofollow".
More options
Starting values
Leave blank to use the widget's defaults. Visitors can still change every value.

Live preview

Exactly what your visitors will see

Embed code

<iframe src="https://a2z.tools/embed/w/ev-charging-cost" title="EV Charging Cost Calculator by A2Z Tools" width="100%" height="800" style="border:0;width:100%" loading="lazy" allow="clipboard-write"></iframe>

A plain iframe. Works everywhere, including site builders that strip scripts. Adjust height if your content needs more room.

Works with

How it works

The energy that ends up in the battery is its capacity times the change in charge level. Charging is not lossless - the on-board charger, cables and battery turn part of the energy into heat - so the energy bought from the grid is that figure divided by the charging efficiency the visitor enters. With the car's own consumption figure the widget also works out the range added and the running cost per 100 km or 100 miles. The consumption to enter is the battery-side figure from the car's trip computer: US EPA label figures are measured at the wall and already include charging losses, so using them here would count the losses twice.

Calculation method

  • Energy into the battery (kWh) = capacity x (to% - from%) / 100
  • Energy from the grid (kWh) = energy into the battery / charging efficiency
  • Cost = grid energy x price per kWh; full charge = capacity / efficiency x price
  • Range added = battery energy / consumption x 100; cost per 100 = consumption / efficiency x price

Worked examples

Home top-up from 20% to 80%

Inputs: 60 kWh battery, 20% to 80%, 90% efficiency, 0.17 per kWh, 17 kWh/100 km

Result: 36 kWh into the battery, 40 kWh from the grid, 6.80 per session; about 212 km added; 3.21 per 100 km

60 x 0.6 = 36; 36 / 0.9 = 40; 40 x 0.17 = 6.80; 17 / 0.9 x 0.17 = 3.21.

Limitations

  • Treats charging efficiency as constant; real losses change with charging power, battery temperature and preconditioning.
  • Uses the usable battery capacity the visitor enters; the widget has no model database.
  • Per-minute, session, idle and membership fees at public chargers are not included.

Where publishers use it

  • EV review and ownership blogs comparing home and public charging
  • Home charger installers' websites
  • Utility pages promoting off-peak EV tariffs
  • Fleet managers estimating the cost of electrifying vans

Questions

What charging efficiency should I use?

Compare the kWh your charger or smart meter reports for a session with the kWh the car says it added; the ratio is your efficiency. Losses are usually higher at very low charging currents and in cold weather.

Which consumption figure should I enter?

The car's own trip-computer figure, which is measured at the battery. The EPA's kWh per 100 miles on US window stickers is measured from the wall and already includes charging losses, so using it here would count the losses twice.

Why charge only to 80%?

Many owners charge to 80% day to day to reduce battery wear and because charging slows near full. Enter any levels you like.

Does it work for public rapid chargers?

Yes - enter that charger's price per kWh. Some networks also charge per minute or per session, which is not included.

Sources

  1. Fuel economy and EV range testing - US Environmental Protection Agency . EPA electricity consumption is measured from the wall, including charging losses

Cite or recommend this tool

If you reference this tool in an article, course or documentation, these formats are ready to copy. They are optional - nothing is added to your site unless you paste it.

A2Z Tools EV Charging Cost Calculator
https://a2z.tools/embed/ev-charging-cost

Related widgets

More Travel & Auto widgets →

Preview

CustomizeGet code