How Many 1/0 AWG THHN Fit in Conduit?
Maximum number of 1/0 AWG THHN/THWN-2 conductors per conduit trade size and type, per NEC 2023 Annex C.
| Trade Size | EMT | RMC | IMC | PVC40 | PVC80 | FMC |
|---|---|---|---|---|---|---|
| 1/2" | 1 | 1 | 1 | 1 | - | 1 |
| 3/4" | 1 | 1 | 1 | 1 | 1 | 1 |
| 1" | 1 | 1 | 1 | 1 | 1 | 1 |
| 1-1/4" | 3 | 3 | 3 | 3 | 2 | 2 |
| 1-1/2" | 4 | 4 | 4 | 4 | 3 | 3 |
| 2" | 7 | 7 | 8 | 7 | 6 | 7 |
| 2-1/2" | 12 | 10 | 11 | 10 | 9 | 10 |
| 3" | 19 | 16 | 17 | 15 | 14 | 15 |
| 3-1/2" | 25 | 21 | 23 | 21 | 18 | 20 |
| 4" | 32 | 27 | 29 | 27 | 24 | 27 |
Counts are for 1/0 AWG THHN/THWN-2 of the same size. Green = 3+ conductors (typical circuit). Equipment grounding conductors must be counted separately.
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NEC 2023 references verified April 2026