Free to use, no account
EV Charging Calculator
Estimate energy, time and optional electricity cost for an electric-car charge. Set battery capacity, starting and target charge, charger input power and an efficiency assumption.
How do you estimate EV charging time?
Calculate the battery energy between the starting and target charge percentages, divide by charging efficiency to estimate energy from the grid, then divide by charger input power. For a 50 kWh pack from 20% to 80%, 30 kWh reaches the battery; at 90% efficiency, about 33.33 kWh comes from the grid.
Frequently asked questions
How do you estimate EV charging time?
Calculate the battery energy between the starting and target charge percentages, divide by charging efficiency to estimate energy from the grid, then divide by charger input power. For a 50 kWh pack from 20% to 80%, 30 kWh reaches the battery; at 90% efficiency, about 33.33 kWh comes from the grid.
Are my vehicle or electricity details uploaded?
No. This estimate runs locally in your browser. Your inputs are not sent to a server or saved by this tool.
Why is the estimate different from my car display?
This model assumes constant input power and one efficiency value. Many vehicles taper power as the battery fills, and temperature, battery conditioning, charger limits and shared circuits also affect actual time.
How is the optional charging cost calculated?
The estimate multiplies grid energy by the electricity rate you enter. It excludes time-of-use periods, taxes, session fees, subscriptions and other tariff rules.