6 AWG Conduit Fill by Conduit Size

How many 6 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

1 6 AWG THHN conductors fit in 1/2 inch EMT and 4 fit in 3/4 inch EMT, at 40% fill for three or more conductors. Each conductor consumes 0.0507 sq in from a nominal insulated outside diameter of 0.254 in. Neutrals and grounds count.

6 AWG conductors per conduit trade size

Same-size conductors only, at 53% for one, 31% for two and 40% for three or more.

Conduit1/2"3/4"1"1-1/4"1-1/2"2"2-1/2"3"3-1/2"4"
EMT146111626466991116
IMC247121728406283107
RMC147121626385979101
PVC Sch 4014611152537577699
PVC Sch 801359132232506888
Published standard — source: Raceway internal areas from product standards (EMT, IMC, RMC, PVC Sch 40, PVC Sch 80); conductor OD from nominal THHN dimensions

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 6 AWG: the classic 3/4 inch versus 1 inch decision

6 AWG is the size that generates the most conduit questions on the job, because three conductors plus a ground sit right at the boundary between 3/4 inch and 1 inch. Whether the run fits depends on how many conductors are in it, not on the circuit rating.

For 60 A subpanel feeders and 48 A EV chargers, the usual answer is 1 inch raceway: it satisfies fill with margin, tolerates the bend radius, and leaves room if a circuit is added later. Sizing a 6 AWG raceway exactly to the fill limit is legal and generally regretted.

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.

Frequently asked

How many 6 AWG wires fit in 1/2 inch EMT?
1 6 AWG THHN conductors fit in 1/2 inch EMT at the applicable fill percentage.
How many 6 AWG wires fit in 3/4 inch EMT?
4 conductors, using a nominal THHN outside diameter of 0.254 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 6 AWG THHN?
About 0.0507 square inches, from A = π × (OD / 2)² with a nominal insulated OD of 0.254 in.

More on 6 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.

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