Electrical metallic tubing fill chart
The most THHN wires of one size each EMT 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2" | 0.304 | 0.122 | 12 | 9 | 5 | 3 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
| 3/4" | 0.533 | 0.213 | 22 | 16 | 10 | 6 | 4 | 2 | 1 | 1 | 0 | 0 | 0 |
| 1" | 0.864 | 0.346 | 35 | 26 | 16 | 9 | 7 | 4 | 3 | 1 | 1 | 1 | 0 |
| 1-1/4" | 1.496 | 0.598 | 61 | 45 | 28 | 16 | 12 | 7 | 5 | 3 | 1 | 1 | 1 |
| 1-1/2" | 2.036 | 0.814 | 84 | 61 | 38 | 22 | 16 | 10 | 7 | 4 | 1 | 1 | 1 |
| 2" | 3.356 | 1.342 | 138 | 101 | 63 | 36 | 26 | 16 | 11 | 7 | 4 | 3 | 1 |
| 2-1/2" | 5.858 | 2.343 | 241 | 176 | 111 | 64 | 46 | 28 | 20 | 12 | 7 | 6 | 3 |
| 3" | 8.846 | 3.538 | 364 | 266 | 167 | 96 | 69 | 43 | 30 | 19 | 11 | 9 | 5 |
| 3-1/2" | 11.545 | 4.618 | 476 | 347 | 219 | 126 | 91 | 56 | 40 | 25 | 14 | 11 | 6 |
| 4" | 14.753 | 5.901 | 608 | 443 | 279 | 161 | 116 | 71 | 51 | 32 | 18 | 15 | 8 |
Areas in square inches, from Chapter 9, Table 4 (2023 NEC). THHN/THWN-2 areas from Table 5.
About EMT
EMT is the thin-wall steel tubing most commercial work uses. It is strapped within 3 ft of each box and every 10 ft (358.30), and joined with set-screw or compression couplings. See strap spacing and the fill rules.