1-1/4" IMC conduit fill
1-1/4" Intermediate metal conduit has an inside area of 1.647 sq in (1.448 in across). Three or more wires may take 40 % of it: 0.6588 sq in.
- One wire, 53 %
- 0.8729 sq in
- Two wires, 31 %
- 0.5106 sq in
- Three or more, 40 %
- 0.6588 sq in
- Nipple, 60 %
- 0.9882 sq in
- Support
- Every 10 ft, 3 ft from boxes
- Sold in
- 10 ft sticks
How many wires fit in 1-1/4" IMC
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 | 68 | 47 | 47 |
| 12 AWG | 49 | 36 | 36 |
| 10 AWG | 31 | 27 | 27 |
| 8 AWG | 18 | 15 | 15 |
| 6 AWG | 13 | 11 | 9 |
| 4 AWG | 8 | 8 | 6 |
| 3 AWG | 6 | 7 | 6 |
| 2 AWG | 5 | 5 | 5 |
| 1 AWG | 4 | 4 | 3 |
| 1/0 AWG | 3 | 3 | 3 |
| 2/0 AWG | 3 | 3 | 1 |
| 3/0 AWG | 1 | 1 | 1 |
| 4/0 AWG | 1 | 1 | 1 |
| 250 kcmil | 1 | 1 | 1 |
| 300 kcmil | 1 | 1 | 1 |
| 350 kcmil | 1 | 1 | 1 |
| 400 kcmil | 1 | 1 | 1 |
| 500 kcmil | 1 | 1 | 1 |
| 600 kcmil | 1 | 1 | 0 |
Other 1-1/4" conduit
| Conduit | Inside area | #14 | #12 | #10 | #8 | #6 |
|---|---|---|---|---|---|---|
| Intermediate metal conduit | 1.647 | 68 | 49 | 31 | 18 | 13 |
| Electrical metallic tubing | 1.496 | 61 | 45 | 28 | 16 | 12 |
| Rigid metal conduit (RMC, GRC) | 1.526 | 63 | 46 | 29 | 16 | 12 |
| Rigid PVC conduit, Schedule 40 | 1.453 | 60 | 43 | 27 | 16 | 11 |
| Rigid PVC conduit, Schedule 80 | 1.237 | 51 | 37 | 23 | 13 | 9 |
| Flexible metal conduit (FMC, Greenfield) | 1.277 | 52 | 38 | 24 | 14 | 10 |
| Liquidtight flexible metal conduit (LFMC) | 1.528 | 63 | 46 | 29 | 16 | 12 |
| Electrical nonmetallic tubing (smurf tube) | 1.453 | 60 | 43 | 27 | 16 | 11 |
About IMC
IMC has a thinner wall than rigid, so it has a little more room inside size for size. Support follows 342.30: within 3 ft of each box, then every 10 ft, or longer on straight runs with threaded couplings. See strap spacing and the fill rules.