How many 8 AWG wires fit in 1/2 inch EMT?

3 8 AWG THHN conductors fit in 1/2 inch EMT at the applicable fill percentage.

How many 8 AWG wires fit in 3/4 inch EMT?

5 conductors, using a nominal THHN outside diameter of 0.216 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 8 AWG THHN?

About 0.0366 square inches, from A = π × (OD / 2)² with a nominal insulated OD of 0.216 in.

8 AWG Conduit Fill by Conduit Size

How many 8 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 8 AWG THHN conductors fit in 1/2 inch EMT and 5 fit in 3/4 inch EMT, at 40% fill for three or more conductors. Each conductor consumes 0.0366 sq in from a nominal insulated outside diameter of 0.216 in. Neutrals and grounds count.

8 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	3	5	9	16	22	36	63	96	126	161
IMC	3	6	10	17	24	39	56	86	115	148
RMC	3	5	9	16	22	37	53	81	109	140
PVC Sch 40	3	5	9	15	21	35	51	79	106	137
PVC Sch 80	1	4	7	13	18	31	44	70	94	122

Published standard

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 8 AWG: counts collapse into single digits

8 AWG is the size where the numbers on this page become small enough to matter for design. A 1/2 inch raceway holds only a couple of conductors, and a typical 40 to 50 A circuit with two ungrounded conductors, a neutral and a ground is normally pulled in 3/4 inch or 1 inch.

Because 8 AWG is stranded and stiff, bend radius joins fill as a real constraint. A short 1/2 inch stub with two 90 degree bends can be legal on fill and still be unpullable, which is why range, spa and EV charger raceways are commonly upsized a trade size at the panel end.

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 8 AWG wires fit in 1/2 inch EMT?: 3 8 AWG THHN conductors fit in 1/2 inch EMT at the applicable fill percentage.
How many 8 AWG wires fit in 3/4 inch EMT?: 5 conductors, using a nominal THHN outside diameter of 0.216 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 8 AWG THHN?: About 0.0366 square inches, from A = π × (OD / 2)² with a nominal insulated OD of 0.216 in.

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.