NEC 2026
PVC Schedule 40 Conduit Fill Chart
PVC Schedule 40 (NEC Article 352) is the standard-wall rigid nonmetallic conduit used underground and in wet or corrosive spots. The tables show the most wires that fit in each trade size at the NEC 2026 fill limit.
Updated
For reference only. Always verify with the NEC edition adopted by your AHJ.
PVC Schedule 40 fill: THHN / THWN-2
| Wire size | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | 3-1/2" | 4" | 5" | 6" |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| #14 | 11 | 21 | 34 | 60 | 82 | 135 | 193 | 299 | 401 | 517 | 815 | 1178 |
| #12 | 8 | 15 | 25 | 43 | 59 | 99 | 141 | 218 | 293 | 377 | 594 | 859 |
| #10 | 5 | 9 | 15 | 27 | 37 | 62 | 89 | 137 | 184 | 238 | 374 | 541 |
| #8 | 3 | 5 | 9 | 16 | 21 | 36 | 51 | 79 | 106 | 137 | 216 | 312 |
| #6 | 1 | 4 | 6 | 11 | 15 | 26 | 37 | 57 | 77 | 99 | 156 | 225 |
| #4 | 1 | 1 | 4 | 7 | 9 | 16 | 22 | 35 | 47 | 61 | 96 | 138 |
| #3 | 1 | 1 | 3 | 6 | 8 | 13 | 19 | 30 | 40 | 51 | 81 | 117 |
| #2 | 1 | 1 | 3 | 5 | 7 | 11 | 16 | 25 | 33 | 43 | 68 | 98 |
| #1 | — | 1 | 1 | 3 | 5 | 8 | 12 | 18 | 25 | 32 | 50 | 73 |
| #1/0 | — | 1 | 1 | 3 | 4 | 7 | 10 | 15 | 21 | 27 | 42 | 61 |
| #2/0 | — | 1 | 1 | 2 | 3 | 6 | 8 | 13 | 17 | 22 | 35 | 51 |
| #3/0 | — | 1 | 1 | 1 | 3 | 5 | 7 | 11 | 14 | 18 | 29 | 42 |
| #4/0 | — | — | 1 | 1 | 1 | 4 | 6 | 9 | 12 | 15 | 24 | 35 |
| 250 kcmil | — | — | 1 | 1 | 1 | 3 | 4 | 7 | 10 | 12 | 20 | 28 |
| 300 kcmil | — | — | — | 1 | 1 | 3 | 4 | 6 | 8 | 11 | 17 | 24 |
| 350 kcmil | — | — | — | 1 | 1 | 1 | 3 | 5 | 7 | 9 | 15 | 21 |
| 400 kcmil | — | — | — | 1 | 1 | 1 | 3 | 5 | 6 | 8 | 13 | 19 |
| 500 kcmil | — | — | — | 1 | 1 | 1 | 2 | 4 | 5 | 7 | 11 | 16 |
— means a single conductor of that size does not fit.
PVC Schedule 40 fill: XHHW-2
| Wire size | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | 3-1/2" | 4" | 5" | 6" |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| #14 | 8 | 14 | 24 | 42 | 57 | 94 | 135 | 209 | 280 | 361 | 568 | 822 |
| #12 | 6 | 11 | 18 | 32 | 44 | 72 | 103 | 160 | 215 | 277 | 436 | 631 |
| #10 | 4 | 8 | 13 | 24 | 32 | 54 | 77 | 119 | 160 | 206 | 325 | 470 |
| #8 | 2 | 4 | 7 | 13 | 18 | 30 | 43 | 66 | 89 | 115 | 181 | 261 |
| #6 | 1 | 3 | 5 | 10 | 13 | 22 | 32 | 49 | 66 | 85 | 134 | 193 |
| #4 | 1 | 1 | 4 | 7 | 9 | 16 | 23 | 35 | 48 | 61 | 97 | 140 |
| #3 | 1 | 1 | 3 | 6 | 8 | 13 | 19 | 30 | 40 | 52 | 82 | 118 |
| #2 | 1 | 1 | 3 | 5 | 7 | 11 | 16 | 25 | 34 | 44 | 69 | 99 |
| #1 | — | 1 | 1 | 3 | 5 | 8 | 12 | 19 | 25 | 32 | 51 | 74 |
| #1/0 | — | 1 | 1 | 3 | 4 | 7 | 10 | 16 | 21 | 27 | 43 | 62 |
| #2/0 | — | 1 | 1 | 2 | 3 | 6 | 8 | 13 | 17 | 23 | 36 | 52 |
| #3/0 | — | 1 | 1 | 1 | 3 | 5 | 7 | 11 | 14 | 19 | 30 | 43 |
| #4/0 | — | — | 1 | 1 | 1 | 4 | 6 | 9 | 12 | 15 | 24 | 35 |
| 250 kcmil | — | — | 1 | 1 | 1 | 3 | 5 | 7 | 10 | 13 | 20 | 29 |
| 300 kcmil | — | — | — | 1 | 1 | 3 | 4 | 6 | 8 | 11 | 17 | 25 |
| 350 kcmil | — | — | — | 1 | 1 | 1 | 3 | 5 | 7 | 9 | 15 | 22 |
| 400 kcmil | — | — | — | 1 | 1 | 1 | 3 | 5 | 6 | 8 | 13 | 19 |
| 500 kcmil | — | — | — | 1 | 1 | 1 | 2 | 4 | 5 | 7 | 11 | 16 |
— means a single conductor of that size does not fit.
PVC Schedule 40 fill: THW
| Wire size | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | 3-1/2" | 4" | 5" | 6" |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| #14 | 8 | 14 | 24 | 42 | 57 | 94 | 135 | 209 | 280 | 361 | 568 | 822 |
| #12 | 6 | 11 | 18 | 32 | 44 | 72 | 103 | 160 | 215 | 277 | 436 | 631 |
| #10 | 4 | 8 | 13 | 24 | 32 | 54 | 77 | 119 | 160 | 206 | 325 | 470 |
| #8 | 2 | 4 | 7 | 13 | 18 | 30 | 43 | 66 | 89 | 115 | 181 | 261 |
| #6 | 1 | 2 | 4 | 8 | 11 | 18 | 26 | 40 | 53 | 69 | 109 | 157 |
| #4 | 1 | 1 | 3 | 6 | 8 | 13 | 19 | 30 | 40 | 51 | 81 | 117 |
| #3 | 1 | 1 | 3 | 5 | 7 | 11 | 16 | 25 | 34 | 44 | 69 | 100 |
| #2 | 1 | 1 | 1 | 4 | 6 | 10 | 14 | 22 | 29 | 37 | 59 | 85 |
| #1 | — | 1 | 1 | 3 | 4 | 7 | 10 | 15 | 20 | 26 | 41 | 60 |
| #1/0 | — | 1 | 1 | 2 | 3 | 6 | 8 | 13 | 17 | 22 | 35 | 51 |
| #2/0 | — | 1 | 1 | 1 | 3 | 5 | 7 | 11 | 15 | 19 | 30 | 43 |
| #3/0 | — | — | 1 | 1 | 1 | 4 | 6 | 9 | 12 | 16 | 25 | 36 |
| #4/0 | — | — | 1 | 1 | 1 | 3 | 5 | 8 | 10 | 13 | 21 | 30 |
| 250 kcmil | — | — | — | 1 | 1 | 3 | 4 | 6 | 8 | 11 | 17 | 25 |
| 300 kcmil | — | — | — | 1 | 1 | 1 | 3 | 5 | 7 | 9 | 15 | 21 |
| 350 kcmil | — | — | — | 1 | 1 | 1 | 3 | 5 | 6 | 8 | 13 | 19 |
| 400 kcmil | — | — | — | 1 | 1 | 1 | 3 | 4 | 6 | 7 | 12 | 17 |
| 500 kcmil | — | — | — | — | 1 | 1 | 1 | 3 | 5 | 6 | 10 | 14 |
— means a single conductor of that size does not fit.
Pick a trade size
PVC Schedule 40 conduit fill questions
- How many #12 THHN wires fit in 1/2" PVC Schedule 40 conduit?
- Up to 8 #12 THHN/THWN-2 conductors fit in 1/2" PVC Schedule 40 under NEC 2026 Chapter 9 (40% fill for three or more wires).
- How many #12 THHN wires fit in 3/4" PVC Schedule 40 conduit?
- Up to 15 #12 THHN/THWN-2 conductors fit in 3/4" PVC Schedule 40 under NEC 2026 Chapter 9 (40% fill for three or more wires).
- How many #12 THHN wires fit in 1" PVC Schedule 40 conduit?
- Up to 25 #12 THHN/THWN-2 conductors fit in 1" PVC Schedule 40 under NEC 2026 Chapter 9 (40% fill for three or more wires).
- What is the fill limit for PVC Schedule 40?
- The same NEC 2026 Chapter 9 Table 1 limits apply to every raceway: 53% of the inside area for one wire, 31% for two and 40% for three or more. PVC Schedule 40 only changes the inside area, from Table 4.
- Does a short PVC Schedule 40 nipple get more fill?
- Yes. Chapter 9 Note 4 allows 60% fill for a nipple 24 inches or shorter between boxes or enclosures. The chart above uses the normal limits.
Other conduit types
You can read the NEC 2026 for free at NFPA free access. Need a different combination? Use the conduit fill calculator.