NEC 2026

PVC Schedule 80 Conduit Fill Chart

PVC Schedule 80 (NEC Article 352) has a thicker wall than Schedule 40, so it holds fewer wires in the same trade size. The tables show the most wires that fit in each trade size at the NEC 2026 fill limit.

Updated

For reference only. Always verify with the NEC edition adopted by your AHJ.

PVC Schedule 80 fill: THHN / THWN-2

Maximum THHN / THWN-2 conductors in PVC Schedule 80, by wire size and trade size
Wire size1/2"3/4"1"1-1/4"1-1/2"2"2-1/2"3"3-1/2"4"5"6"
#149172851701181702653584647361055
#1261220375186124193261338537770
#10471323325478122164213338485
#8147131831457095123195279
#61359132232516889141202
#411368142031425486124
#311357121726354673105
#2—114610142230396188
#1—11347101622294565
#1/0—1123691418243855
#2/0——113571115203246
#3/0——11146913172638
#4/0——11135810142231
250 kcmil———113468111825
300 kcmil———11135791522
350 kcmil———11135681319
400 kcmil———11134671217
500 kcmil————1113561014

— means a single conductor of that size does not fit.

PVC Schedule 80 fill: XHHW-2

Maximum XHHW-2 conductors in PVC Schedule 80, by wire size and trade size
Wire size1/2"3/4"1"1-1/4"1-1/2"2"2-1/2"3"3-1/2"4"5"6"
#1461119354982118185250324514736
#12491527386391142192248394565
#10361120284768106143185294421
#8136111526375979103163234
#61248111928435976121173
#411368142031425587125
#311357121726364774106
#21114610142230396289
#1—11347101622294666
#1/0—1123691419243956
#2/0——113571116203246
#3/0——11246913172738
#4/0——11135811142232
250 kcmil———113469111826
300 kcmil———111357101522
350 kcmil———11135681420
400 kcmil———11134671217
500 kcmil————1113561014

— means a single conductor of that size does not fit.

PVC Schedule 80 fill: THW

Maximum THW conductors in PVC Schedule 80, by wire size and trade size
Wire size1/2"3/4"1"1-1/4"1-1/2"2"2-1/2"3"3-1/2"4"5"6"
#1461119354982118185250324514736
#12491527386391142192248394565
#10361120284768106143185294421
#8136111526375979103163234
#611379162235486298141
#411357121726354673105
#31114610142230396390
#2—11358121926335377
#1—1123681318233754
#1/0——113571115203246
#2/0——112461013172739
#3/0——11135811142333
#4/0———113479121927
250 kcmil———11135791522
300 kcmil———11135681319
350 kcmil———11124671217
400 kcmil————1114571015
500 kcmil————111345913

— means a single conductor of that size does not fit.

Pick a trade size

PVC Schedule 80 conduit fill questions

How many #12 THHN wires fit in 1/2" PVC Schedule 80 conduit?
Up to 6 #12 THHN/THWN-2 conductors fit in 1/2" PVC Schedule 80 under NEC 2026 Chapter 9 (40% fill for three or more wires).
How many #12 THHN wires fit in 3/4" PVC Schedule 80 conduit?
Up to 12 #12 THHN/THWN-2 conductors fit in 3/4" PVC Schedule 80 under NEC 2026 Chapter 9 (40% fill for three or more wires).
How many #12 THHN wires fit in 1" PVC Schedule 80 conduit?
Up to 20 #12 THHN/THWN-2 conductors fit in 1" PVC Schedule 80 under NEC 2026 Chapter 9 (40% fill for three or more wires).
What is the fill limit for PVC Schedule 80?
The same NEC 2026 Chapter 9 Table 1 limits apply to every raceway: 53% of the inside area for one wire, 31% for two and 40% for three or more. PVC Schedule 80 only changes the inside area, from Table 4.
Does a short PVC Schedule 80 nipple get more fill?
Yes. Chapter 9 Note 4 allows 60% fill for a nipple 24 inches or shorter between boxes or enclosures. The chart above uses the normal limits.

Other conduit types

You can read the NEC 2026 for free at NFPA free access. Need a different combination? Use the conduit fill calculator.