Base table size
12 AWGCopper EGC for an overcurrent device not exceeding 20 A.
Equipment Grounding Conductor Calculator
Equipment Grounding Conductor Calculator
Size a wire-type equipment grounding conductor and apply proportional adjustment when phase conductors are increased. New here? Read the quick guide.
Equipment Grounding Conductor Calculation
Report details
Grounding inputs and sizing result
- Project
- —
- Circuit
- —
- Prepared by
- —
- Revision
- —
- Protective device
- 20 A
- Phase conductors
- 3 × 12 AWG Copper · stranded
- Minimum phase size
- 12 AWG
- EGC material / construction
- Copper · stranded
Calculated decision
- Base table EGC
- 12 AWG
- Phase-area ratio
- × 1
- Required EGC area
- 6,530 cmil
- Final wire-type EGC
- 12 AWG Copper
This calculator addresses one wire-type EGC in one non-parallel raceway through 600 A. Verify the adopted code, effective ground-fault-current path, wiring method, material restrictions, special equipment rules, taps, motors, and AHJ requirements.
Calculation inputs
Circuit protection
Project information for worksheet
Transparent calculation
How the grounding size was selected
Use both conductor rows in Conduit Size
Continue to Conduit SizeTransfers 3 × 12 AWG Copper phase conductors and 1 × 12 AWG Copper equipment grounding conductor.
Phase-conductor increase
× 112 AWG installed area ÷ 12 AWG minimum area.
Required EGC area
6,530 cmil6,530 cmil × 1.
Final standard size
12 AWGNext supported conductor area meeting or exceeding the calculated requirement.
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The PDF and CSV retain the base table size, proportional adjustment, final standard size, and project context.
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The destination opens with compatible conduit and cable inputs already selected. This calculator and its results remain unchanged.
Method and scope
What this result establishes
The result reproduces the supported portion of 2023 NEC Table 250.122 and applies proportional circular-mil adjustment when the installed phase conductor is larger than the entered minimum.
Required verification
What remains outside this calculator
It does not determine the overcurrent device, phase-conductor ampacity, raceway-as-EGC suitability, fault-current performance, parallel-raceway rules, motor or tap provisions, material installation restrictions, or final code compliance.