PVC Conduit Fill Chart (Sch 40 & Sch 80)
Maximum conductors per PVC Schedule 40 and Schedule 80 trade size, NEC 2023 Chapter 9.
PVC Schedule 80 has the same outside diameter as Sch 40 but a thicker wall — so the interior area, and the wire fill, is smaller. Switch between Sch 40 and Sch 80 in the dropdown below to compare. For mixed-wire combinations, use the conduit fill calculator.
| TRADE → WIRE ↓ | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | 3-1/2" | 4" | 5" | 6" |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 14 AWG | 11 | 20 | 34 | 59 | 81 | 135 | 193 | 299 | 401 | 517 | 814 | 1000 |
| 12 AWG | 8 | 15 | 25 | 43 | 59 | 98 | 141 | 218 | 292 | 377 | 594 | 859 |
| 10 AWG | 5 | 9 | 15 | 27 | 37 | 62 | 89 | 137 | 184 | 237 | 374 | 541 |
| 8 AWG | 3 | 5 | 9 | 15 | 21 | 35 | 51 | 79 | 106 | 137 | 215 | 312 |
| 6 AWG | 1 | 4 | 6 | 11 | 15 | 25 | 37 | 57 | 76 | 99 | 155 | 225 |
| 4 AWG | 1 | 1 | 4 | 7 | 9 | 15 | 22 | 35 | 47 | 60 | 95 | 138 |
| 3 AWG | 1 | 1 | 3 | 5 | 8 | 13 | 19 | 29 | 40 | 51 | 81 | 117 |
| 2 AWG | 1 | 1 | 2 | 5 | 6 | 11 | 16 | 25 | 33 | 43 | 68 | 98 |
| 1 AWG | — | 1 | 1 | 3 | 5 | 8 | 12 | 18 | 24 | 32 | 50 | 73 |
| 1/0 | — | 1 | 1 | 3 | 4 | 7 | 10 | 15 | 20 | 27 | 42 | 61 |
| 2/0 | — | 1 | 1 | 2 | 3 | 5 | 8 | 13 | 17 | 22 | 35 | 51 |
| 3/0 | — | 1 | 1 | 1 | 2 | 4 | 7 | 10 | 14 | 18 | 29 | 42 |
| 4/0 | — | — | 1 | 1 | 1 | 4 | 5 | 8 | 12 | 15 | 24 | 35 |
| 250 | — | — | 1 | 1 | 1 | 3 | 4 | 7 | 9 | 12 | 19 | 28 |
| 300 | — | — | — | 1 | 1 | 2 | 4 | 6 | 8 | 10 | 17 | 24 |
| 350 | — | — | — | 1 | 1 | 1 | 3 | 5 | 7 | 9 | 15 | 21 |
| 400 | — | — | — | 1 | 1 | 1 | 3 | 4 | 6 | 8 | 13 | 19 |
| 500 | — | — | — | 1 | 1 | 1 | 2 | 4 | 5 | 7 | 11 | 16 |
| 600 | — | — | — | — | 1 | 1 | 1 | 3 | 4 | 5 | 9 | 13 |
| 700 | — | — | — | — | 1 | 1 | 1 | 2 | 3 | 5 | 7 | 11 |
| 750 | — | — | — | — | 1 | 1 | 1 | 2 | 3 | 4 | 7 | 10 |
| 800 | — | — | — | — | — | 1 | 1 | 2 | 3 | 4 | 7 | 10 |
| 900 | — | — | — | — | — | 1 | 1 | 1 | 3 | 4 | 6 | 9 |
| 1000 | — | — | — | — | — | 1 | 1 | 1 | 2 | 3 | 5 | 8 |
PVC Schedule 40 × THHN (90°C dry) · NEC 2023 Ch.9 Tables 4 & 5 · 40% (3+), 31% (2), 53% (1)
NOTES & CONTEXT
PVC Schedule 40 vs Schedule 80
Both are rigid nonmetallic conduit covered by NEC Article 352. Schedule 40 is standard for direct burial, exposed work in dry locations, and concrete encasement. Schedule 80 is required wherever the conduit is exposed to physical damage (e.g., the first 8 ft of a riser, vehicle traffic areas).
At 1": Sch 40 has 0.832 in² interior versus Sch 80's 0.688 in². At 40% fill, that's a 17% reduction in capacity — so a Sch 80 riser may need one trade size larger than the Sch 40 it transitions from.
PVC wire fill calculation notes
- PVC has no temperature derating advantage — fill rules are identical to metallic conduit (53/31/40 %).
- Sunlight exposure: PVC sleeve and conductors should be sunlight-resistant rated (SR or SLR) above grade.
- Expansion: per NEC 352.44, PVC needs expansion fittings if the temperature swing × length × coefficient exceeds 1/4".
Common PVC conduit fill scenarios
- Buried 200-amp service in PVC Sch 80: 3 × 4/0 + 1 × 2 AWG copper THHN fits 1-1/2".
- Pool feeder with 4 × 8 AWG THHN: 3/4" Sch 80 fits comfortably.
- Underground branch to detached garage, 6 × 12 AWG THHN: 1/2" Sch 40 fits 9, so 6 is fine.