4" PVC Sch 80 conduit fill

4" Rigid PVC conduit, Schedule 80 has an inside area of 11.258 sq in (3.786 in across). Three or more wires may take 40 % of it: 4.5032 sq in.

One wire, 53 %: 5.9667 sq in
Two wires, 31 %: 3.4900 sq in
Three or more, 40 %: 4.5032 sq in
Nipple, 60 %: 6.7548 sq in
Support: Every 7 ft, 3 ft from boxes
Sold in: 10 ft sticks

54 #4 THHN, the most it may hold, drawn to scale

How many wires fit in 4" PVC Sch 80

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	464	324	324
12 AWG	338	248	248
10 AWG	213	185	185
8 AWG	123	103	103
6 AWG	89	76	62
4 AWG	54	55	46
3 AWG	46	47	39
2 AWG	39	39	33
1 AWG	29	29	23
1/0 AWG	24	24	20
2/0 AWG	20	20	17
3/0 AWG	17	17	14
4/0 AWG	14	14	12
250 kcmil	11	11	9
300 kcmil	9	10	8
350 kcmil	8	8	7
400 kcmil	7	7	7
500 kcmil	6	6	5
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: 3-1/2" PVC Sch 80 Bigger: 5" PVC Sch 80

Other 4" conduit

Conduit	Inside area	#14	#12	#10	#8	#6
Rigid PVC conduit, Schedule 80	11.258	464	338	213	123	89
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
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 PVC Sch 80

Schedule 80 has a thicker wall for where it can be hit, so it holds fewer wires than Schedule 40 of the same trade size. Support is the same as Schedule 40 (Table 352.30). See strap spacing and the fill rules.