EV Charger Circuit Calculator

Recommend the breaker and circuit size for an EV charger continuous load.

Breaker Size
— amp breaker
NEC 125% continuous rule.

Usage Tip

Match the wire gauge to the breaker, and confirm your panel has room for a double-pole 240 V breaker before buying the charger.

THE MATH
continuous load = charger amps
breaker = round up( charger amps ÷ 0.8 )
An EV charger runs at full current for hours, so it is a continuous load. Code sizes the breaker and wire at 125 percent of that load, the same as dividing by 0.8.
Enter the charger output amps and the circuit voltage (240 V for most home chargers).
The result rounds up to the next standard breaker size.
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