How many 16 AWG wires fit in 1/2 inch EMT?

16 16 AWG THHN conductors fit in 1/2 inch EMT at the applicable fill percentage.

How many 16 AWG wires fit in 3/4 inch EMT?

29 conductors, using a nominal THHN outside diameter of 0.096 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 16 AWG THHN?

About 0.0072 square inches, from A = π × (OD / 2)² with a nominal insulated OD of 0.096 in.

16 AWG Conduit Fill by Conduit Size

How many 16 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

16 16 AWG THHN conductors fit in 1/2 inch EMT and 29 fit in 3/4 inch EMT, at 40% fill for three or more conductors. Each conductor consumes 0.0072 sq in from a nominal insulated outside diameter of 0.096 in. Neutrals and grounds count.

16 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	16	29	47	82	112	185	200	200	200	200
IMC	18	32	52	91	122	200	200	200	200	200
RMC	17	30	49	84	114	188	200	200	200	200
PVC Sch 40	15	28	45	80	109	181	200	200	200	200
PVC Sch 80	12	22	38	68	94	158	200	200	200	200

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 16 AWG: derating arrives before geometry

16 AWG occupies so little raceway area that conductor-count derating becomes the binding limit long before the fill percentage does. Once more than three current-carrying conductors share the raceway, the adjustment factor cuts ampacity even though the tube is nowhere near full.

That makes 16 AWG a bundling problem rather than a fill problem. Typical uses are fixture whips, control cabling and appliance leads, where the design question is how many circuits share a raceway, not how many conductors physically fit inside it.

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 16 AWG wires fit in 1/2 inch EMT?: 16 16 AWG THHN conductors fit in 1/2 inch EMT at the applicable fill percentage.
How many 16 AWG wires fit in 3/4 inch EMT?: 29 conductors, using a nominal THHN outside diameter of 0.096 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 16 AWG THHN?: About 0.0072 square inches, from A = π × (OD / 2)² with a nominal insulated OD of 0.096 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.