Conduit Fill Calculator
NEC Chapter 9. EMT conduit — fill % vs the 53% / 31% / 40% limits.
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NEC fill limits (Chapter 9, Table 1)
- 1 wire: max
53%of conduit area - 2 wires: max
31% - 3+ wires: max
40%(all conductors counted, incl. grounds) - Conduit IDs from NEC Chapter 9, Table 4 (EMT); wire diameters for THHN/THWN per Table 5.
- Jamming: avoid pulling 3 wires where
D/dis between 2.8 and 3.2.