Home EV Charger Size Calculator
Estimate available charging power and time from supply type, current limit, voltage and vehicle AC charging limit.
How the calculation works
Estimate available charging power and time from supply type, current limit, voltage and vehicle AC charging limit. Change every input to match your vehicle, equipment, tariff or measured consumption.
Worked example
A 400 V three-phase circuit at 16 A provides about 11.1 kW, normally described as an 11 kW charger.
What can change the result?
- The main connection must retain capacity for household loads.
- Dynamic load balancing can reduce charger power when the home uses more electricity.
- Cable and breaker selection must be completed by a qualified electrician.
Frequently asked questions
Will a 22 kW wallbox charge every EV at 22 kW?
No. Many vehicles accept only 7.4 or 11 kW AC, so the vehicle becomes the limit.
Can I use all current available at the main breaker?
Usually not safely without considering other loads and diversity. Seek an electrical assessment.
Why can real charging power be slightly lower?
Voltage, onboard charger behaviour, thermal conditions and load balancing can reduce measured power.
Use the result responsibly
This calculator is intended for comparison and planning. Verify equipment limits, tariffs and important electrical decisions with the manufacturer, energy supplier or a qualified professional.