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How Many Wires Fit in 1/2 in PVC Schedule 40?

Largest same-size THHN counts for 1/2 in PVC Schedule 40, with expansion, sunlight and burial caveats beyond percent fill.
Raceway
PVC Schedule 40
Trade size
1/2 in
Default limit
40% for 3 or more
Method
Chapter 9 area

Same-Size THHN Counts

Uniform conductor examples for quick planning. Mixed pulls need the calculator.

Conductor sizeInsulationLargest passing countFill at that countCaveat
14 AWGTHHN / THWN-21137.4%Uniform-size example only
12 AWGTHHN / THWN-2837.3%Uniform-size example only
10 AWGTHHN / THWN-2537%Uniform-size example only
8 AWGTHHN / THWN-2338.5%Uniform-size example only
6 AWGTHHN / THWN-2117.8%Uniform-size example only
4 AWGTHHN / THWN-2128.9%Uniform-size example only
2 AWGTHHN / THWN-2140.6%Uniform-size example only
How Many Wires Fit in 1/2 in PVC Schedule 40?. Counts are computed from the same fill engine as the calculator and rounded down to the largest passing whole count.

What the 1/2 in PVC Count Actually MeansSame-size THHN counts use Chapter 9 Table 4 area for PVC Schedule 40 at the applicable percent fill. Schedule 80 has less internal area — do not use these counts for Schedule 80.

Run mixed-size conduit fill

Adjacent Trade Sizes

How 12 AWG THHN counts change across neighboring PVC Schedule 40 sizes.

Trade size12 AWG THHN count10 AWG THHN count8 AWG THHN count
1/2 in (this page)853
3/4 in1595
Largest passing same-size 12 AWG THHN counts for neighboring PVC Schedule 40 trade sizes.

Where 1/2 in PVC Schedule 40 Is Used

PVC Schedule 40 installation context for 1/2 in.

PVC Schedule 40 is common for underground and corrosive locations. Fill counts for 1/2 in look similar to other raceways at a glance, but internal area differs by type — never borrow an EMT count for PVC.

Sunlight resistance, burial depth, support and expansion fittings are outside the fill calculator. A PVC run can pass fill and still be the wrong product outdoors.

What Changes the Count

Checks that matter for PVC Schedule 40 — not a shared six-bullet list.

  • Schedule 40 vs 80

    These counts are Schedule 40 only. Schedule 80 needs its own Table 4 areas.

  • Expansion and temperature

    Long PVC runs need expansion fittings where required. Fill success does not replace expansion design.

  • Burial and physical protection

    Underground and emerging-from-grade rules can require Schedule 80 or other protection regardless of fill.

  • Mixed pulls

    Mixed conductor sizes still need group-by-group area sums in the calculator.

1/2 in PVC Schedule 40 FAQs

How many wires fit in 1/2 inch PVC Schedule 40?
Use the same-size THHN counts on this page. For mixed sizes or other insulation types, run the conduit fill calculator with PVC Schedule 40 selected.
Can I use EMT fill numbers for PVC?
No. Internal areas differ by raceway type even at the same trade size.
Does this cover PVC Schedule 80?
No. Schedule 80 has different internal area. Select Schedule 80 in the calculator instead of using these Schedule 40 counts.