PVC Schedule 80 Conduit Fill Chart

Rigid PVC Conduit, Schedule 80 — NEC Article 352. Heavy-wall PVC required where conduit is exposed to physical damage, such as risers on poles and service masts. Same outside diameter as Schedule 40, so the thicker wall takes noticeably more room from the inside.

1/2-inch PVC Schedule 80 holds 6 #12 THHN conductors; 3/4-inch holds 12. Counts assume 40% fill with all conductors the same size.

PVC Schedule 80 fill calculator

Conduit type

Trade size

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

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PVC Schedule 80 sizes

One page per trade size, with counts for every insulation type side by side.

PVC Schedule 80 fill chart — THHN / THWN-2

Thermoplastic insulation with a nylon jacket. The thinnest common building wire, so it gives the highest conductor counts. Nearly all pulled wire sold in North America is dual-rated THHN/THWN-2.

Maximum THHN conductors in PVC Schedule 80 — 40% fill (53% for one wire, 31% for two)
Wire size	1/2"	3/4"	1"	1-1/4"	1-1/2"	2"	2-1/2"	3"	3-1/2"	4"	5"	6"
14 AWG	9	17	28	51	70	118	170	265	358	464	736	1055
12 AWG	6	12	20	37	51	86	124	193	261	338	537	770
10 AWG	4	7	13	23	32	54	78	122	164	213	338	485
8 AWG	1	4	7	13	18	31	45	70	95	123	195	279
6 AWG	1	3	5	9	13	22	32	51	68	89	141	202
4 AWG	1	1	3	6	8	14	20	31	42	54	86	124
3 AWG	1	1	3	5	7	12	17	26	35	46	73	105
2 AWG	—	1	1	4	6	10	14	22	30	39	61	88
1 AWG	—	1	1	3	4	7	10	16	22	29	45	65
1/0 AWG	—	1	1	2	3	6	9	14	18	24	38	55
2/0 AWG	—	—	1	1	3	5	7	11	15	20	32	46
3/0 AWG	—	—	1	1	1	4	6	9	13	17	26	38
4/0 AWG	—	—	1	1	1	3	5	8	10	14	22	31
250 kcmil	—	—	—	1	1	3	4	6	8	11	18	25
300 kcmil	—	—	—	1	1	1	3	5	7	9	15	22
350 kcmil	—	—	—	1	1	1	3	5	6	8	13	19
400 kcmil	—	—	—	1	1	1	3	4	6	7	12	17
500 kcmil	—	—	—	—	1	1	1	3	5	6	10	14
600 kcmil	—	—	—	—	1	1	1	3	4	5	8	12
700 kcmil	—	—	—	—	—	1	1	2	3	4	7	10
750 kcmil	—	—	—	—	—	1	1	1	3	4	7	9
800 kcmil	—	—	—	—	—	1	1	1	3	4	6	9
900 kcmil	—	—	—	—	—	1	1	1	3	3	6	8
1000 kcmil	—	—	—	—	—	1	1	1	1	3	5	7

PVC Schedule 80 fill chart — XHHW / XHHW-2

Cross-linked polyethylene (XLPE) insulation, no nylon jacket. Standard for aluminum feeders and common for larger copper feeders. Slightly fatter than THHN in small sizes, slightly thinner above 4 AWG.

Maximum XHHW conductors in PVC Schedule 80 — 40% fill (53% for one wire, 31% for two)
Wire size	1/2"	3/4"	1"	1-1/4"	1-1/2"	2"	2-1/2"	3"	3-1/2"	4"	5"	6"
14 AWG	6	11	19	35	49	82	118	185	250	324	514	736
12 AWG	4	9	15	27	38	63	91	142	192	248	394	565
10 AWG	3	6	11	20	28	47	68	106	143	185	294	421
8 AWG	1	3	6	11	15	26	37	59	79	103	163	234
6 AWG	1	2	4	8	11	19	28	43	59	76	121	173
4 AWG	1	1	3	6	8	14	20	31	42	55	87	125
3 AWG	1	1	3	5	7	12	17	26	36	47	74	106
2 AWG	1	1	1	4	6	10	14	22	30	39	62	89
1 AWG	—	1	1	3	4	7	10	16	22	29	46	66
1/0 AWG	—	1	1	2	3	6	9	14	19	24	39	56
2/0 AWG	—	—	1	1	3	5	7	11	16	20	32	46
3/0 AWG	—	—	1	1	2	4	6	9	13	17	27	38
4/0 AWG	—	—	1	1	1	3	5	8	11	14	22	32
250 kcmil	—	—	—	1	1	3	4	6	9	11	18	26
300 kcmil	—	—	—	1	1	1	3	5	7	10	15	22
350 kcmil	—	—	—	1	1	1	3	5	6	8	14	20
400 kcmil	—	—	—	1	1	1	3	4	6	7	12	17
500 kcmil	—	—	—	—	1	1	1	3	5	6	10	14
600 kcmil	—	—	—	—	1	1	1	3	4	5	8	11
700 kcmil	—	—	—	—	—	1	1	2	3	4	7	10
750 kcmil	—	—	—	—	—	1	1	1	3	4	6	9
800 kcmil	—	—	—	—	—	1	1	1	3	4	6	9
900 kcmil	—	—	—	—	—	1	1	1	3	3	5	8
1000 kcmil	—	—	—	—	—	1	1	1	1	3	5	7

PVC Schedule 80 fill chart — THW / THHW / TW

Older thick-wall thermoplastic insulation without a nylon jacket. Rarely installed new, but it is what you will find in many existing conduits, and it takes considerably more room than THHN.

Maximum THW conductors in PVC Schedule 80 — 40% fill (53% for one wire, 31% for two)
Wire size	1/2"	3/4"	1"	1-1/4"	1-1/2"	2"	2-1/2"	3"	3-1/2"	4"	5"	6"
14 AWG	6	11	19	35	49	82	118	185	250	324	514	736
12 AWG	4	9	15	27	38	63	91	142	192	248	394	565
10 AWG	3	6	11	20	28	47	68	106	143	185	294	421
8 AWG	1	3	6	11	15	26	37	59	79	103	163	234
6 AWG	1	1	3	7	9	16	22	35	48	62	98	141
4 AWG	1	1	3	5	7	12	17	26	35	46	73	105
3 AWG	1	1	1	4	6	10	14	22	30	39	63	90
2 AWG	—	1	1	3	5	8	12	19	26	33	53	77
1 AWG	—	1	1	2	3	6	8	13	18	23	37	54
1/0 AWG	—	—	1	1	3	5	7	11	15	20	32	46
2/0 AWG	—	—	1	1	2	4	6	10	13	17	27	39
3/0 AWG	—	—	1	1	1	3	5	8	11	14	23	33
4/0 AWG	—	—	—	1	1	3	4	7	9	12	19	27
250 kcmil	—	—	—	1	1	1	3	5	7	9	15	22
300 kcmil	—	—	—	1	1	1	3	5	6	8	13	19
350 kcmil	—	—	—	1	1	1	2	4	6	7	12	17
400 kcmil	—	—	—	—	1	1	1	4	5	7	10	15
500 kcmil	—	—	—	—	1	1	1	3	4	5	9	13
600 kcmil	—	—	—	—	—	1	1	2	3	4	7	10
700 kcmil	—	—	—	—	—	1	1	1	3	4	6	9
750 kcmil	—	—	—	—	—	1	1	1	3	4	6	8
800 kcmil	—	—	—	—	—	1	1	1	3	3	6	8
900 kcmil	—	—	—	—	—	1	1	1	1	3	5	7
1000 kcmil	—	—	—	—	—	1	1	1	1	3	5	7

PVC Schedule 80 fill chart — RHH / RHW-2

Thermoset rubber-type insulation with an outer covering. The bulkiest of the common types; counts drop to roughly half of THHN in small conduit.

Maximum RHW conductors in PVC Schedule 80 — 40% fill (53% for one wire, 31% for two)
Wire size	1/2"	3/4"	1"	1-1/4"	1-1/2"	2"	2-1/2"	3"	3-1/2"	4"	5"	6"
14 AWG	3	5	9	17	23	39	56	88	118	153	243	349
12 AWG	1	4	7	14	19	32	46	73	98	127	202	290
10 AWG	1	3	6	11	15	26	37	59	79	103	163	234
8 AWG	1	1	3	6	8	13	19	31	41	54	85	122
6 AWG	1	1	2	4	6	11	16	24	33	43	68	98
4 AWG	—	1	1	3	5	8	12	19	26	33	53	77
3 AWG	—	1	1	3	4	7	11	17	23	29	47	67
2 AWG	—	1	1	3	4	6	9	14	20	25	41	58
1 AWG	—	—	1	1	1	4	6	9	13	17	27	38
1/0 AWG	—	—	1	1	1	3	5	8	11	15	23	33
2/0 AWG	—	—	1	1	1	3	4	7	10	13	20	29
3/0 AWG	—	—	—	1	1	3	4	6	8	11	17	25
4/0 AWG	—	—	—	1	1	1	3	5	7	9	15	21
250 kcmil	—	—	—	1	1	1	2	4	5	7	11	16
300 kcmil	—	—	—	—	1	1	1	3	5	6	10	14
350 kcmil	—	—	—	—	1	1	1	3	4	5	9	13
400 kcmil	—	—	—	—	1	1	1	3	4	5	8	12
500 kcmil	—	—	—	—	—	1	1	1	3	4	7	10
600 kcmil	—	—	—	—	—	1	1	1	3	3	6	8
700 kcmil	—	—	—	—	—	1	1	1	1	3	5	7
750 kcmil	—	—	—	—	—	1	1	1	1	3	5	7
800 kcmil	—	—	—	—	—	1	1	1	1	3	4	7
900 kcmil	—	—	—	—	—	—	1	1	1	2	4	6
1000 kcmil	—	—	—	—	—	—	1	1	1	1	4	5

PVC Schedule 80 internal diameter and area

PVC Schedule 80 internal dimensions and allowable fill area
Trade size	Metric designator	Internal dia. (in)	Total area (in²)	1 wire — 53%	2 wires — 31%	Over 2 — 40%	Nipple — 60%
1/2"	16	0.526	0.217	0.115	0.067	0.087	0.130
3/4"	21	0.722	0.409	0.217	0.127	0.164	0.245
1"	27	0.936	0.688	0.365	0.213	0.275	0.413
1-1/4"	35	1.255	1.237	0.656	0.383	0.495	0.742
1-1/2"	41	1.476	1.711	0.907	0.530	0.684	1.027
2"	53	1.913	2.874	1.523	0.891	1.150	1.724
2-1/2"	63	2.290	4.119	2.183	1.277	1.648	2.471
3"	78	2.864	6.442	3.414	1.997	2.577	3.865
3-1/2"	91	3.326	8.688	4.605	2.693	3.475	5.213
4"	103	3.786	11.258	5.967	3.490	4.503	6.755
5"	129	4.768	17.855	9.463	5.535	7.142	10.713
6"	155	5.709	25.598	13.567	7.935	10.239	15.359

Fill limits that apply

Allowable conduit fill (Chapter 9, Table 1 and its notes)
Conductors in the raceway	Maximum fill	Why
1	53%	A single conductor cannot jam, so more of the area can be used.
2	31%	Two conductors lie side by side and wedge easily in bends, so the limit is lowest.
3 or more	40%	The everyday limit. Leaves room to pull and for heat to escape.
Nipple ≤ 24 in.	60%	Short sections between boxes or enclosures; derating for conductor count does not apply either.

Frequently asked questions

How many #12 wires can I put in 1/2-inch PVC Schedule 80?

6 conductors of 12 AWG THHN/THWN-2, or 4 of the thicker THW. In 3/4-inch PVC Schedule 80 the count rises to 12 THHN.

How many #10 wires fit in 1/2-inch PVC Schedule 80?

4 conductors of 10 AWG THHN in 1/2-inch, and 7 in 3/4-inch.

What is the inside diameter of 3/4-inch PVC Schedule 80?

0.722 inches, giving a total internal area of 0.409 in² and 0.164 in² of usable area at 40% fill.

What is the largest wire that fits in 6-inch PVC Schedule 80?

6-inch PVC Schedule 80 holds 14 conductors of 500 kcmil THHN or 7 of 1000 kcmil.

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.