Conduit Fill
NEC Chapter 9, Table 1 (53% / 31% / 40%), Table 4 raceway areas and Table 5 conductor areas.
Conductors
Fill by trade size
Max same-size conductors
THHN/THWN-2 areas also apply to THWN. XHHW areas apply to XHHW-2. Count EGCs in fill. Nipples 24 in. or shorter may be filled to 60% (Note 4). Same-size counts round up when the decimal is 0.8 or more (Note 7).
Reference only — not engineering, legal, or code-compliance advice. Results are estimates for qualified persons and must be verified against the NEC edition adopted where the work is done (your selected edition), manufacturer instructions, and the local AHJ. Use is subject to the Terms of Use & Disclaimer. — Morningstar Electric LLC