NEC 2026 — 210.19(A) Two-Pass · Tables 310.16–310.20
Calculator Type
Derivation — NEC Table 310.16 · NEC 210.19(A) Two-Pass
NEC 210.19(A)(1) / 215.2(A)(1) / 430.24
Continuous Load (Amperes)
Non-Continuous Load (Amperes)
Motor Loads
NEC Table 310.16
Conditions of Use
Material
Terminal Temperature Rating — Pass 1
Drives Pass 1 column (NEC Table 310.16). NEC 110.14(C): terminals ≤ 100 A → 60°C; > 100 A → 75°C. Motor loads always force 75°C. Override only if terminals are listed for a higher rating.
NEC Table 310.16
Insulation Temperature Rating — Pass 2 (NEC Table 310.16)
Drives Pass 2 column (NEC Table 310.16) — the actual insulation rating of the conductor being installed. Defaults to 90°C; select a lower rating if using 60°C or 75°C-rated insulation.
NEC 310.15(B)(1) / Table 310.15(B)(1)(1)
Ambient Temperature
NEC 310.15(C)(1) / Table 310.15(C)(1)
Current-Carrying Conductors in Raceway / Cable
Count only current-carrying conductors. Neutral conductors carrying only unbalanced current, and EGCs, are typically not counted.
Minimum Conductor Size
Enter all inputs above to see the minimum conductor size.
Additional Scenarios
Disclaimer
This calculator is an independent tool intended to assist electrical professionals. It enforces NEC 110.14(C) terminal temperature limits and covers ampacity correction and adjustment per NEC 310.15(B)/(C) using the two-pass method per NEC 210.19(A), as well as equipment grounding conductor sizing per NEC Table 250.122 (including 250.122(B) upsizing and 250.122(F) parallel-run requirements), and grounding electrode conductor sizing per NEC Table 250.66 (including the 250.66(A)-(C) electrode-specific size caps). It does not evaluate every condition of use (cable trays, direct burial, free-air spacing, etc.), voltage drop, or overcurrent protection sizing under 240.4. Always verify final conductor sizing against the complete 2023 NEC text and applicable local amendments. NEC® and NFPA 70® are registered trademarks and copyrighted publications of the National Fire Protection Association.