EMT Conduit Fill Chart
Maximum conductors per Electrical Metallic Tubing (EMT) trade size, NEC 2023 Chapter 9.
This is the complete EMT wire fill chart, computed live from NEC 2023 Chapter 9 Tables 4 and 5. Pick an insulation, filter by wire size, then download as CSV or print. For interactive multi-wire calculations use the conduit fill calculator.
- 1/2" EMT9 wires
- 3/4" EMT16 wires
- 1" EMT26 wires
- 1-1/4" EMT45 wires
- 1-1/2" EMT61 wires
- 2" EMT101 wires
- 2-1/2" EMT176 wires
- 3" EMT266 wires
- 3-1/2" EMT347 wires
- 4" EMT443 wires
| TRADE → WIRE ↓ | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | 3-1/2" | 4" |
|---|---|---|---|---|---|---|---|---|---|---|
| 14 AWG | 12 | 22 | 35 | 61 | 84 | 138 | 241 | 364 | 476 | 608 |
| 12 AWG | 9 | 16 | 26 | 45 | 61 | 101 | 176 | 266 | 347 | 443 |
| 10 AWG | 5 | 10 | 16 | 28 | 38 | 63 | 111 | 167 | 219 | 279 |
| 8 AWG | 3 | 6 | 9 | 16 | 22 | 36 | 64 | 96 | 126 | 161 |
| 6 AWG | 2 | 4 | 7 | 12 | 16 | 26 | 46 | 69 | 91 | 116 |
| 4 AWG | — | 2 | 4 | 7 | 10 | 16 | 28 | 43 | 56 | 71 |
| 3 AWG | 1 | — | 3 | 6 | 8 | 13 | 24 | 36 | 47 | 60 |
| 2 AWG | 1 | — | 3 | 5 | 7 | 11 | 20 | 30 | 40 | 51 |
| 1 AWG | 1 | — | — | 4 | 5 | 8 | 15 | 22 | 29 | 37 |
| 1/0 | 1 | 1 | — | 3 | 4 | 7 | 12 | 19 | 25 | 32 |
| 2/0 | — | 1 | — | 2 | 3 | 6 | 10 | 16 | 20 | 26 |
| 3/0 | — | 1 | 1 | — | 3 | 5 | 8 | 13 | 17 | 22 |
| 4/0 | — | 1 | 1 | — | 2 | 4 | 7 | 11 | 14 | 18 |
| 250 | — | — | 1 | — | — | 3 | 6 | 9 | 11 | 15 |
| 300 | — | — | 1 | 1 | — | 3 | 5 | 7 | 10 | 13 |
| 350 | — | — | 1 | 1 | — | 2 | 4 | 6 | 9 | 11 |
| 400 | — | — | — | 1 | — | — | 4 | 6 | 8 | 10 |
| 500 | — | — | — | 1 | 1 | — | 3 | 5 | 6 | 8 |
| 600 | — | — | — | 1 | 1 | — | 2 | 4 | 5 | 7 |
| 700 | — | — | — | 1 | 1 | 1 | 2 | 3 | 4 | 6 |
| 750 | — | — | — | — | 1 | 1 | — | 3 | 4 | 5 |
| 800 | — | — | — | — | 1 | 1 | — | 3 | 4 | 5 |
| 900 | — | — | — | — | 1 | 1 | — | 3 | 3 | 4 |
| 1000 | — | — | — | — | 1 | 1 | — | 2 | 3 | 4 |
EMT — Electrical Metallic Tubing × THHN (90°C dry) · NEC 2023 Ch.9 Tables 4 & 5 · 40% (3+), 31% (2), 53% (1)
NOTES & CONTEXT
How to use the EMT conduit fill chart
Find your wire size in the leftmost column. Read across to the EMT trade size you plan to install. The cell shows the maximum number of conductors of the chosen insulation that NEC 2023 permits in that conduit. A dash (—) means the cell exceeds NEC limits even with one conductor (very large wire / small conduit).
What is EMT?
Electrical Metallic Tubing (EMT) is a thin-wall galvanized steel raceway covered by NEC Article 358. It's the most common conduit in US commercial work because it's cheap, light, and easily bent on-site with a hand bender. EMT is rated for both exposed and concealed work in dry, damp, and (with proper fittings) wet locations.
Why EMT wire fill matters
Overfilling EMT causes three problems: heat buildup (insulation degrades faster), pulling tension (cables nick on the inside of bends), and jam risk (three same-size cables can wedge at the conduit/wire OD ratio of about 2.8 to 3.2). The NEC limits are conservative but well-tested — 40% for three or more conductors gives enough room for heat dissipation and safe pulls.
EMT vs IMC vs RMC fill differences
At the same trade size, EMT, IMC, and RMC all have different interior areas — thicker walls mean less room. A 1" EMT holds 0.864 in² versus 0.959 in² for 1" IMC and 0.887 in² for 1" RMC. The chart adjusts automatically when you switch conduit type; see the rigid conduit fill chart for IMC and RMC values.
Common EMT wire fill scenarios
- 3-wire residential branch circuit (12 AWG THHN): 1/2" EMT fits 9 — easy capacity for a single 20-amp run.
- Home run with 6 conductors of 12 AWG THHN (2 circuits + ground): Still inside 1/2" EMT (6 of 9 allowed).
- Feeder with 4 conductors of 3/0 THHN: Needs 1-1/2" EMT minimum.
- Service entrance with 4 conductors of 4/0 THHN: Needs 2" EMT.
Heat de-rating note
The EMT wire fill chart accounts only for the physical fit. If you bundle four or more current-carrying conductors in a conduit longer than 24 inches, NEC Table 310.15(C)(1) requires you to derate ampacity (80% for 4–6 conductors, 70% for 7–9, etc.) — independent of whether the fill % is within limits.