3 AWG Conduit Fill by Conduit Size
How many 3 AWG THHN conductors fit in EMT, IMC, RMC and PVC conduit, 1/2 inch through 4 inch, with the 40% fill rule applied.
Quick answer
3 AWG conductors per conduit trade size
Same-size conductors only, at 53% for one, 31% for two and 40% for three or more.
| Conduit | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | 3-1/2" | 4" |
|---|---|---|---|---|---|---|---|---|---|---|
| EMT | 1 | 1 | 3 | 6 | 8 | 13 | 24 | 36 | 47 | 60 |
| IMC | 1 | 1 | 3 | 6 | 9 | 14 | 21 | 32 | 43 | 56 |
| RMC | 1 | 1 | 3 | 6 | 8 | 14 | 19 | 30 | 41 | 52 |
| PVC Sch 40 | 1 | 1 | 3 | 5 | 8 | 13 | 19 | 29 | 40 | 51 |
| PVC Sch 80 | 1 | 1 | 2 | 5 | 7 | 11 | 16 | 26 | 35 | 46 |
Source & method: Counts are the largest whole number where n × conductor area stays inside the raceway area times the applicable fill percentage. Mix conductor sizes in the calculator.
Fill behaviour at 3 AWG: an interval size in raceway terms too
3 AWG rarely drives raceway design because it is rarely specified, but the counts are useful for one case: checking whether an existing conduit can be reused. Where a calculation lands between 4 AWG and 2 AWG, 3 AWG occasionally fits a raceway that 2 AWG will not.
For new work the sensible approach is to size the raceway for 2 AWG anyway. The material cost difference is small, availability is better, and the raceway then tolerates a future upsize without a rebuild.
Source & method: Counts referenced above come from the computed table on this page — how these numbers are derived.
What each raceway type means
- EMT — EMT (electrical metallic tubing)
- IMC — IMC (intermediate metal conduit)
- RMC — RMC (rigid metal conduit)
- PVC Sch 40 — PVC Schedule 40
- PVC Sch 80 — PVC Schedule 80
Full fill charts by raceway
Per-type counts for every trade size, plus the cross-type comparison and reverse lookup.
- EMT conduit fill chart — 1/2" to 4"Electrical metallic tubing, thinnest wall, highest count per trade size.
- Conduit fill chart — all raceway types comparedEMT, IMC, RMC, PVC 40 and PVC 80 side by side with reverse lookup.
- PVC conduit fill chart — Schedule 40 and 80Thicker walls, roughly 15 to 25% fewer conductors than tubing.
- Rigid conduit fill chart — RMC and IMCThreaded metal raceway counts and usable areas.
Frequently asked
- How many 3 AWG wires fit in 1/2 inch EMT?
- 1 3 AWG THHN conductors fit in 1/2 inch EMT at the applicable fill percentage.
- How many 3 AWG wires fit in 3/4 inch EMT?
- 1 conductors, using a nominal THHN outside diameter of 0.352 in and the 40% fill rule for three or more conductors.
- Do neutrals and grounds count toward fill?
- Yes, every conductor in the raceway counts for fill. Grounds are excluded only from the count of current-carrying conductors used for ampacity adjustment.
- What is the cross-sectional area of 3 AWG THHN?
- About 0.0973 square inches, from A = π × (OD / 2)² with a nominal insulated OD of 0.352 in.
More on 3 AWG
Conduit fill for nearby sizes
Same 40% fill rule applied to the sizes either side of this one, wrapping around the range so every size is reachable.
Related charts & calculators
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- Voltage Drop CalculatorPercent drop, end voltage and minimum conductor for any run length.
- Conduit Fill CalculatorFill percentage and maximum conductor count for EMT, RMC, IMC and PVC.
- Breaker Size CalculatorOvercurrent device rating and minimum conductor from load current.
- Wire Ampacity CalculatorDerated ampacity for ambient temperature and bundled conductors.