Terms & Disclaimer
Not professional engineering advice
These calculators are provided for educational, design-planning and general informational purposes only. They do not constitute professional engineering advice or a recommendation for licensed installation. Codes and electrical regulations vary by jurisdiction, and actual installation must be carried out by a licensed electrician in accordance with the code enforced locally. Misuse of these results can cause electrical fire, equipment damage or code violations. The NEC table values on this site reflect NEC 2023; the 2026 edition has not been verified. Verify every value against the edition of the NEC in force in your area.
Code editions change
The National Electrical Code is revised on a three-year cycle and is adopted with local amendments. Always verify against the edition enforced in your jurisdiction.
Values still pending verification
Numeric tables used by these calculators are being checked against the code text and reviewed by a licensed electrician. Until that review is complete and credited on the Methodology page, results should be treated as unreviewed.