Liquidtight flexible metal conduit (LFMC) fill chart
The most THHN wires of one size each Liquidtight size may hold, with three or more wires at 40 % fill. Pick a size for XHHW-2 and THW as well.
| Trade size | Inside area | 40 % | #14 | #12 | #10 | #8 | #6 | #4 | #2 | #1/0 | #4/0 | 250 kcmil | 500 kcmil |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3/8" | 0.192 | 0.077 | 8 | 5 | 3 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
| 1/2" | 0.314 | 0.126 | 13 | 9 | 6 | 3 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
| 3/4" | 0.541 | 0.216 | 22 | 16 | 10 | 6 | 4 | 2 | 1 | 1 | 0 | 0 | 0 |
| 1" | 0.873 | 0.349 | 36 | 26 | 16 | 9 | 7 | 4 | 3 | 1 | 1 | 1 | 0 |
| 1-1/4" | 1.528 | 0.611 | 63 | 46 | 29 | 16 | 12 | 7 | 5 | 3 | 1 | 1 | 1 |
| 1-1/2" | 1.981 | 0.792 | 81 | 59 | 37 | 21 | 15 | 9 | 7 | 4 | 1 | 1 | 1 |
| 2" | 3.246 | 1.298 | 134 | 97 | 61 | 35 | 25 | 15 | 11 | 7 | 4 | 3 | 1 |
| 2-1/2" | 4.881 | 1.952 | 201 | 146 | 92 | 53 | 38 | 23 | 17 | 10 | 6 | 5 | 2 |
| 3" | 7.475 | 2.990 | 308 | 225 | 141 | 81 | 59 | 36 | 26 | 16 | 9 | 7 | 4 |
| 3-1/2" | 9.731 | 3.892 | 401 | 292 | 184 | 106 | 76 | 47 | 33 | 21 | 12 | 10 | 5 |
| 4" | 12.692 | 5.077 | 523 | 381 | 240 | 138 | 100 | 61 | 44 | 27 | 15 | 12 | 7 |
Areas in square inches, from Chapter 9, Table 4 (2023 NEC). THHN/THWN-2 areas from Table 5.
About Liquidtight
Liquidtight is supported every 4-1/2 ft and within 12 in of each box (350.30), with exceptions for short lengths at equipment. See strap spacing and the fill rules.