Sizing an EV charger circuit — the 125% chain from charger to wire
EV charging is continuous by definition: EVSE amps × 125% → breaker → wire. Above 40 A output, hardwired only; plug-in installs need GFCI.
What this diagram shows
Flow diagram of EV charger circuit sizing per NEC Article 625: a 48-amp EVSE is a continuous load, multiplied by 125 percent to require 60 amps of capacity, which selects a 60-amp double-pole breaker and 6 AWG copper THHN in conduit (or 4 AWG NM-B). Above 40 amps of output the charger must be hardwired; at or below 40 amps a NEMA 14-50 receptacle is permitted with GFCI protection per 625.54.
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EV Charger Circuit Calculator
What wire and breaker does your EV charger need? Free NEC Article 625 calculator by EVSE amps — 125% rule, hardwire vs plug, GFCI, and run length.
