Estimate EV charging time between percentages
The required battery energy is capacity multiplied by the difference between starting and target charge. Charging time divides that energy by charger power adjusted for the efficiency you enter.
For a 60 kWh battery going from 20% to 80%, the required stored energy is 36 kWh. At 7.2 kW and 90% efficiency, the constant-power estimate is about 5.56 hours. Real charging can slow as the battery fills.
What is this calculator?
Estimate charging time from battery capacity and charger power.
What can you use it for?
Use it for practical planning, conversions, measurement or checking the result described here. Estimate charging time from battery capacity and charger power.
How to use it
- Enter battery capacity (kwh).
- Enter starting charge (%).
- Enter target charge (%).
- Enter charger power (kw).
- Enter charging efficiency (%).
- Select Calculate (or Generate for random tools).
- Read the answer and any additional results below the form. Check the units and the limits of the method.
Formula and method
The formula uses the units and definitions shown above. Each input is substituted before the arithmetic is evaluated; the calculated output is rounded for display.
Worked example
Battery capacity (kWh): 60, Starting charge (%): 20, Target charge (%): 80, Charger power (kW): 7.2, Charging efficiency (%): 90. The result is 5.55555556 hours (result).
Assumptions and limits
Target charge must be at least starting charge. Constant-power model; real charging tapers.
Frequently asked questions
What inputs does the EV Charging Calculator need?
Use battery capacity (kwh), starting charge (%), target charge (%), charger power (kw), charging efficiency (%). Read the answer and any additional results below the form. Check the units and the limits of the method.
What assumptions apply to the EV Charging Calculator?
Target charge must be at least starting charge. Constant-power model; real charging tapers.