How Many 6 AWG Wires Fit in FMC Conduit?
Complete NEC-compliant fill chart for 6 AWG THHN wires in Flexible Metal Conduit (FMC) conduit. Maximum wire counts for all standard conduit sizes.
Quick Answer
For 6 AWG THHN wires in FMC conduit at 40% fill (3+ wires):
- • 1/2" FMC: 2 wires
- • 3/4" FMC: 4 wires
- • 1" FMC: 6 wires
6 AWG in FMC Conduit Fill Chart
| Conduit Size | Max Wires (40% Fill) | Fill % | Max Wires (Nipple 60%) | Fill % |
|---|---|---|---|---|
| 1/2" | 2 | 34% | 3 | 51% |
| 3/4" | 4 | 40% | 6 | 60% |
| 1" | 6 | 37% | 9 | 56% |
| 1-1/4" | 10 | 37% | 16 | 59% |
| 1-1/2" | 14 | 37% | 22 | 59% |
| 2" | 24 | 39% | 37 | 60% |
| 2-1/2" | 41 | 40% | 62 | 60% |
| 3" | 63 | 39% | 95 | 60% |
| 3-1/2" | 83 | 40% | 125 | 60% |
| 4" | 105 | 40% | 158 | 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 FMC conduit size while maintaining NEC compliance.
Calculation Example
Question: How many 6 AWG THHN wires can fit in 3/4" FMC conduit?
Wire area: 0.0507 sq in per conductor
Conduit internal area: 0.508 sq in
Allowable fill (40%): 0.2032 sq in
Maximum wires: 0.2032 ÷ 0.0507 = 4 wires
Answer: You can fit up to 4 wires of 6 AWG THHN in 3/4" FMC conduit.