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Conduit Fill Calculator
← All tools  NEC Ch. 9 · Tables 1, 4, 5

Raceway Chapter 9, Table 4

Nipple ≤ 24 in. — 60% fill permitted (Ch. 9 Note 4)

Conductors Chapter 9, Table 5 — include the EGC (Note 3)

Equipment grounding and bonding conductors count toward fill (Ch. 9, Note 3). THHN/THWN/THWN-2 share one column; XHHW insulation is thicker — pick the type printed on the jacket.

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Conduit Fill Calculation

Notes & Assumptions

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    This calculation is provided for estimating and permitting support. Final design responsibility rests with the licensed contractor of record and the authority having jurisdiction.
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