How Many 6 AWG Wires Fit in IMC Conduit?
Complete NEC-compliant fill chart for 6 AWG THHN wires in Intermediate Metal Conduit (IMC) conduit. Maximum wire counts for all standard conduit sizes.
Quick Answer
For 6 AWG THHN wires in IMC conduit at 40% fill (3+ wires):
- • 1/2" IMC: 2 wires
- • 3/4" IMC: 4 wires
- • 1" IMC: 7 wires
6 AWG in IMC Conduit Fill Chart
| Conduit Size | Max Wires (40% Fill) | Fill % | Max Wires (Nipple 60%) | Fill % |
|---|---|---|---|---|
| 1/2" | 2 | 30% | 4 | 59% |
| 3/4" | 4 | 35% | 6 | 52% |
| 1" | 7 | 37% | 11 | 58% |
| 1-1/4" | 12 | 37% | 19 | 58% |
| 1-1/2" | 17 | 39% | 26 | 59% |
| 2" | 28 | 39% | 43 | 59% |
| 2-1/2" | 50 | 40% | 75 | 59% |
| 3" | 76 | 40% | 114 | 60% |
| 3-1/2" | 99 | 40% | 148 | 60% |
| 4" | 125 | 40% | 188 | 60% |
Understanding the Fill Chart
According to NEC (National Electrical Code) Chapter 9, Table 1, the maximum conduit fill percentage depends on the number of conductors:
- 1 conductor: 53% fill maximum
- 2 conductors: 31% fill maximum
- 3 or more conductors: 40% fill maximum
- Nipples (24" or less): 60% fill maximum
This chart shows the maximum number of 6 AWG THHN conductors that can fit in each IMC conduit size while maintaining NEC compliance.
Calculation Example
Question: How many 6 AWG THHN wires can fit in 3/4" IMC conduit?
Wire area: 0.0507 sq in per conductor
Conduit internal area: 0.586 sq in
Allowable fill (40%): 0.2344 sq in
Maximum wires: 0.2344 ÷ 0.0507 = 4 wires
Answer: You can fit up to 4 wires of 6 AWG THHN in 3/4" IMC conduit.