2-1/2" Rigid conduit fill
2-1/2" Rigid metal conduit (RMC, GRC) has an inside area of 4.866 sq in (2.489 in across). Three or more wires may take 40 % of it: 1.9464 sq in.
- One wire, 53 %
- 2.5790 sq in
- Two wires, 31 %
- 1.5085 sq in
- Three or more, 40 %
- 1.9464 sq in
- Nipple, 60 %
- 2.9196 sq in
- Support
- Every 10 ft, 3 ft from boxes
- Sold in
- 10 ft sticks
How many wires fit in 2-1/2" Rigid
All wires the same size and type, by Annex C's method. For a mix of sizes, open the calculator.
| Wire size | THHN/THWN-2 | XHHW-2 | THW/THW-2 |
|---|---|---|---|
| 14 AWG | 200 | 140 | 140 |
| 12 AWG | 146 | 107 | 107 |
| 10 AWG | 92 | 80 | 80 |
| 8 AWG | 53 | 44 | 44 |
| 6 AWG | 38 | 33 | 27 |
| 4 AWG | 23 | 24 | 20 |
| 3 AWG | 20 | 20 | 17 |
| 2 AWG | 17 | 17 | 14 |
| 1 AWG | 12 | 12 | 10 |
| 1/0 AWG | 10 | 10 | 8 |
| 2/0 AWG | 8 | 9 | 7 |
| 3/0 AWG | 7 | 7 | 6 |
| 4/0 AWG | 6 | 6 | 5 |
| 250 kcmil | 5 | 5 | 4 |
| 300 kcmil | 4 | 4 | 3 |
| 350 kcmil | 3 | 3 | 3 |
| 400 kcmil | 3 | 3 | 3 |
| 500 kcmil | 2 | 2 | 1 |
| 600 kcmil | 1 | 1 | 1 |
| 700 kcmil | 1 | 1 | 1 |
| 750 kcmil | 1 | 1 | 1 |
| 800 kcmil | 1 | 1 | 1 |
| 900 kcmil | 1 | 1 | 1 |
| 1000 kcmil | 1 | 1 | 1 |
Other 2-1/2" conduit
| Conduit | Inside area | #14 | #12 | #10 | #8 | #6 |
|---|---|---|---|---|---|---|
| Rigid metal conduit (RMC, GRC) | 4.866 | 200 | 146 | 92 | 53 | 38 |
| Electrical metallic tubing | 5.858 | 241 | 176 | 111 | 64 | 46 |
| Intermediate metal conduit | 5.135 | 211 | 154 | 97 | 56 | 40 |
| Rigid PVC conduit, Schedule 40 | 4.695 | 193 | 141 | 89 | 51 | 37 |
| Rigid PVC conduit, Schedule 80 | 4.119 | 170 | 124 | 78 | 45 | 32 |
| Flexible metal conduit (FMC, Greenfield) | 4.909 | 202 | 147 | 93 | 53 | 38 |
| Liquidtight flexible metal conduit (LFMC) | 4.881 | 201 | 146 | 92 | 53 | 38 |
About Rigid
Rigid (galvanized rigid conduit, GRC) has the thickest wall and the least room inside of the steel types. Support follows 344.30: within 3 ft of each box, then every 10 ft, or longer on straight runs with threaded couplings (Table 344.30(B)(2)). See strap spacing and the fill rules.