Ground Wire Size Calculator
Determine the minimum equipment grounding conductor (EGC) size per NEC Table 250.122. Select your OCPD rating and wire material to get started.
NEC Table 250.122
The minimum EGC size is determined by the rating of the overcurrent protective device (OCPD) protecting the circuit — not the conductor size you pulled. This calculator references NEC Table 250.122 directly.
Upsized Conductors (250.122(B))
If you increased your conductor size beyond what's required for ampacity (e.g. for voltage drop), the EGC must be proportionally increased per NEC 250.122(B). Use the upsize fields to calculate the adjusted EGC size.