6-inch PVC Schedule 40 Conduit Fill

Wire capacity of trade size 6 (metric designator 155) Rigid PVC Conduit, Schedule 40, for THHN, XHHW, THW and RHW conductors from 14 AWG to 1000 kcmil.

6-inch PVC Schedule 40 holds 98 × #2, 61 × 1/0 AWG, 35 × 4/0 AWG or 16 × 500 kcmil THHN conductors at 40% fill. Internal area: 28.567 in²; usable at 40%: 11.427 in².

Internal diameter

6.031 in · 153.2 mm

Total area

28.567 in² · 18430 mm²

40% fill (3+ wires)

11.427 in²

31% / 53% (2 / 1 wire)

8.856 / 15.141 in²

Maximum conductors in 6-inch PVC Schedule 40
Wire size	THHN	XHHW	THW	RHW	THHN in a nipple (60%)	THHN area (in²)
14 AWG	1178	822	822	390	1767	0.0097
12 AWG	859	631	631	323	1288	0.0133
10 AWG	541	470	470	261	812	0.0211
8 AWG	312	261	261	137	468	0.0366
6 AWG	225	193	157	109	338	0.0507
4 AWG	138	140	117	85	208	0.0824
3 AWG	117	118	100	75	176	0.0973
2 AWG	98	99	85	65	148	0.1158
1 AWG	73	74	60	43	109	0.1562
1/0 AWG	61	62	51	37	92	0.1855
2/0 AWG	51	52	43	32	77	0.2223
3/0 AWG	42	43	36	28	64	0.2679
4/0 AWG	35	35	30	24	53	0.3237
250 kcmil	28	29	25	18	43	0.3970
300 kcmil	24	25	21	16	37	0.4608
350 kcmil	21	22	19	14	32	0.5242
400 kcmil	19	19	17	13	29	0.5863
500 kcmil	16	16	14	11	24	0.7073
600 kcmil	13	13	11	9	19	0.8676
700 kcmil	11	11	10	8	17	0.9887
750 kcmil	11	11	10	8	16	1.0496
800 kcmil	10	10	9	7	15	1.1085
900 kcmil	9	9	8	7	14	1.2311
1000 kcmil	8	8	7	6	12	1.3478

Mixed wire sizes? Calculate it

Conduit type

Trade size

Run length Nipple, 24 in. or shorter (60%)

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6-inch conduit: PVC Schedule 40 vs other types

Trade size is nominal. The real inside diameter, and so the wire count, changes with the wall thickness of each raceway type.

6-inch trade size across conduit types
Conduit type	ID (in)	Area (in²)	40% (in²)	#12 THHN	#10 THHN	#6 THHN
PVC Schedule 40	6.031	28.567	11.427	859	541	225
PVC Schedule 80	5.709	25.598	10.239	770	485	202
Rigid Metal Conduit	6.093	29.158	11.663	877	552	230

Other PVC Schedule 40 sizes

Frequently asked questions

How many #12 wires fit in 6-inch PVC Schedule 40?

859 conductors of 12 AWG THHN/THWN-2 at the 40% fill limit. With thicker THW or XHHW insulation the count is 631.

What is the inside diameter and area of 6-inch PVC Schedule 40?

The internal diameter is 6.031 in. (153.2 mm) and the total cross-sectional area is 28.567 in². The usable area is 11.427 in² at 40% fill, 8.856 in² for two wires and 15.141 in² for one.

What is the largest wire I can pull three of in 6-inch PVC Schedule 40?

1000 kcmil THHN: 8 conductors fit at 40% fill. That is three current-carrying conductors with no ground; add the ground’s area and check again with the calculator if you need one.

Can I really load it with that many conductors?

For space, yes. But 859 current-carrying conductors in one raceway means heavy ampacity derating — 10 to 20 conductors are adjusted to 50% of their table ampacity. Fill tells you what fits; derating tells you what it can carry.

NECTables.com is an independent reference and is not affiliated with, endorsed by, or a substitute for the National Fire Protection Association (NFPA). NEC® and National Electrical Code® are registered trademarks of the NFPA. Values shown are commonly published engineering data and independent calculations based on the methods of NFPA 70; they are not a reproduction of the Code. Always confirm against the edition adopted in your jurisdiction, including local amendments, and consult a licensed electrician or engineer before doing electrical work.