3-1/2" EMT conduit fill

3-1/2" Electrical metallic tubing has an inside area of 11.545 sq in (3.834 in across). Three or more wires may take 40 % of it: 4.6180 sq in.

One wire, 53 %: 6.1189 sq in
Two wires, 31 %: 3.5789 sq in
Three or more, 40 %: 4.6180 sq in
Nipple, 60 %: 6.9270 sq in
Support: Every 10 ft, 3 ft from boxes
Sold in: 10 ft sticks

56 #4 THHN, the most it may hold, drawn to scale

How many wires fit in 3-1/2" EMT

All wires the same size and type, by Annex C's method. For a mix of sizes, open the calculator.

Wire size	THHN/THWN-2	XHHW-2	THW/THW-2
14 AWG	476	332	332
12 AWG	347	255	255
10 AWG	219	190	190
8 AWG	126	105	105
6 AWG	91	78	63
4 AWG	56	56	47
3 AWG	47	48	40
2 AWG	40	40	34
1 AWG	29	30	24
1/0 AWG	25	25	20
2/0 AWG	20	21	17
3/0 AWG	17	17	15
4/0 AWG	14	14	12
250 kcmil	11	12	10
300 kcmil	10	10	8
350 kcmil	9	9	7
400 kcmil	8	8	7
500 kcmil	6	6	6
600 kcmil	5	5	4
700 kcmil	4	4	4
750 kcmil	4	4	4
800 kcmil	4	4	3
900 kcmil	3	3	3
1000 kcmil	3	3	3

Smaller: 3" EMT Bigger: 4" EMT

Other 3-1/2" conduit

Conduit	Inside area	#14	#12	#10	#8	#6
Electrical metallic tubing	11.545	476	347	219	126	91
Intermediate metal conduit	10.584	436	318	200	115	83
Rigid metal conduit (RMC, GRC)	10.010	412	301	189	109	79
Rigid PVC conduit, Schedule 40	9.737	401	293	184	106	77
Rigid PVC conduit, Schedule 80	8.688	358	261	164	95	68
Flexible metal conduit (FMC, Greenfield)	9.621	396	289	182	105	76
Liquidtight flexible metal conduit (LFMC)	9.731	401	292	184	106	76

About EMT

EMT is the thin-wall steel tubing most commercial work uses. It is strapped within 3 ft of each box and every 10 ft (358.30), and joined with set-screw or compression couplings. See strap spacing and the fill rules.