4" EMT conduit fill

4" Electrical metallic tubing has an inside area of 14.753 sq in (4.334 in across). Three or more wires may take 40 % of it: 5.9012 sq in.

One wire, 53 %: 7.8191 sq in
Two wires, 31 %: 4.5734 sq in
Three or more, 40 %: 5.9012 sq in
Nipple, 60 %: 8.8518 sq in
Support: Every 10 ft, 3 ft from boxes
Sold in: 10 ft sticks

32 #1/0 THHN, the most it may hold, drawn to scale

How many wires fit in 4" 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	608	424	424
12 AWG	443	326	326
10 AWG	279	243	243
8 AWG	161	135	135
6 AWG	116	100	81
4 AWG	71	72	60
3 AWG	60	61	52
2 AWG	51	51	44
1 AWG	37	38	31
1/0 AWG	32	32	26
2/0 AWG	26	27	22
3/0 AWG	22	22	19
4/0 AWG	18	18	16
250 kcmil	15	15	13
300 kcmil	13	13	11
350 kcmil	11	11	10
400 kcmil	10	10	9
500 kcmil	8	8	7
600 kcmil	7	6	6
700 kcmil	6	6	5
750 kcmil	5	5	5
800 kcmil	5	5	5
900 kcmil	4	4	4
1000 kcmil	4	4	4

Smaller: 3-1/2" EMT

Other 4" conduit

Conduit	Inside area	#14	#12	#10	#8	#6
Electrical metallic tubing	14.753	608	443	279	161	116
Intermediate metal conduit	13.631	562	410	258	149	107
Rigid metal conduit (RMC, GRC)	12.882	531	387	244	140	101
Rigid PVC conduit, Schedule 40	12.554	517	377	238	137	99
Rigid PVC conduit, Schedule 80	11.258	464	338	213	123	89
Flexible metal conduit (FMC, Greenfield)	12.566	518	378	238	137	99
Liquidtight flexible metal conduit (LFMC)	12.692	523	381	240	138	100

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.