EV charging cost calculator
See what each charge of your electric car costs at home or at a public charger, including the energy lost while charging.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter usable battery capacity, current charge, target charge, price per kwh and charging efficiency.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Energy into battery = capacity × (target % − current %) ÷ 100. Energy from the grid = energy into battery ÷ charging efficiency; cost = grid energy × price per kWh.
Example
Inputs: Usable battery capacity = 75 kWh, Current charge = 20 %, Target charge = 80 %, Price per kWh = 0.18, Charging efficiency = 90 %. Result: Charging cost: 9.00; Energy drawn from the grid: 50 kWh; Energy added to the battery: 45 kWh.
Limits and caveats
- Charging efficiency is an estimate, usually 85% to 95%, and can drop in very hot or cold weather.
- Use the usable (net) capacity from the car's manual, not the gross capacity.
Questions about this tool
Why do I pay for more than the battery holds?
Part of the electricity turns into heat in the charger and battery, so the grid supplies more energy than the battery stores.
Why charge only to 80%?
Many makers recommend 80% for daily charging to protect the battery, and fast charging slows sharply above that level.
Does the price differ between home and public chargers?
Yes, public fast charging usually costs more than home electricity, so enter the rate where you charge.