NEC Chapter 9 Conduit Fill
How Many Wires Fit in 2" PVC-80?
The maximum THHN conductors per wire size in 2 inch PVC-80 (Schedule 80 PVC) at the NEC 40% fill limit, with the math and the interactive calculator for any mix of wires.
Max THHN Conductors in 2" PVC-80 (40% Fill)
Maximum number of same-size THHN/THWN-2 conductors in 2 inch PVC-80 at the NEC Chapter 9 40% fill limit. Count the equipment ground as a conductor.
| Wire Size (THHN) | Max Conductors | Area Each (sq in) |
|---|---|---|
| #14 AWG | 118 | 0.0097 |
| #12 AWG | 86 | 0.0133 |
| #10 AWG | 54 | 0.0211 |
| #8 AWG | 31 | 0.0366 |
| #6 AWG | 22 | 0.0507 |
| #4 AWG | 14 | 0.0824 |
Based on 2 inch PVC-80 internal area 2.874 sq in (NEC Chapter 9 Table 4). One conductor allows 53% fill, two allow 31%, three or more allow 40% (Table 1).
Mixed Wire Sizes? Calculate It
The chart is for one wire size at a time. For a real pull with mixed sizes, insulation types, or other conduit, enter your exact conductors for the precise fill percentage.
Frequently Asked Questions
How many wires fit in 2 inch PVC-80?
At the NEC 40% fill limit for three or more conductors, 2 inch PVC-80 (internal area 2.874 sq in) holds 86 #12 THHN, 118 #14, 54 #10, or 31 #8 conductors. The math is the conduit area times 0.40 (2.874 × 0.40 = 1.150 sq in allowable), divided by the conductor's area from NEC Chapter 9 Table 5.
How many 12 AWG THHN wires fit in 2 inch PVC-80?
86 #12 THHN conductors fit in 2 inch PVC-80 at the 40% fill limit. Each #12 THHN is 0.0133 sq in, so 1.150 sq in allowable ÷ 0.0133 rounds to 86 conductors (NEC Chapter 9 Note 7 rounds up when the decimal is 0.8 or more). The same count applies to THWN-2, which has the identical area.
How many #10 THHN wires fit in 2 inch PVC-80?
54 #10 THHN conductors fit in 2 inch PVC-80 at the NEC 40% fill limit. Each #10 THHN is 0.0211 sq in, so 1.150 sq in allowable (2.874 × 0.40) ÷ 0.0211 rounds to 54 conductors (NEC Chapter 9 Note 7). THWN-2 has the identical area and gives the same count. Count the equipment ground as a conductor.
How many 14 AWG wires fit in 2 inch PVC-80?
118 #14 THHN conductors fit in 2 inch PVC-80 at 40% fill. Each #14 THHN is 0.0097 sq in, so 1.150 sq in ÷ 0.0097 rounds to 118 (NEC Chapter 9 Note 7). Remember the ground counts as a conductor, and more than three current-carrying conductors trigger ampacity derating per NEC 310.15(C)(1).
What is the fill limit for 2 inch PVC-80?
The maximum fill depends on how many conductors are in the raceway (NEC Chapter 9, Table 1): 53% for one conductor, 31% for two, and 40% for three or more. For 2 inch PVC-80 (internal area 2.874 sq in, Schedule 80 PVC) that is 1.523 sq in for one wire, 0.891 sq in for two, and 1.150 sq in for three or more. The 40% case is the common one.
Fill for Other PVC-80 Sizes
Wires in 1/2" PVC-80
6 #12 THHN and the full count for 1/2 inch pipe.
Wires in 3/4" PVC-80
12 #12 THHN and the full count for 3/4 inch pipe.
Wires in 1" PVC-80
20 #12 THHN and the full count for 1 inch pipe.
Wires in 1-1/4" PVC-80
37 #12 THHN and the full count for 1-1/4 inch pipe.
Wires in 1-1/2" PVC-80
51 #12 THHN and the full count for 1-1/2 inch pipe.
Wires in 2-1/2" PVC-80
124 #12 THHN and the full count for 2-1/2 inch pipe.
Wires in 3" PVC-80
193 #12 THHN and the full count for 3 inch pipe.
Wires in 3-1/2" PVC-80
261 #12 THHN and the full count for 3-1/2 inch pipe.
Wires in 4" PVC-80
338 #12 THHN and the full count for 4 inch pipe.
2" in Other Conduit Types
The same 2 inch trade size holds a different number of wires depending on the conduit type, because each has a different internal area (NEC Chapter 9 Table 4).
2" EMT Fill
101 #12 THHN (EMT (electrical metallic tubing), 3.356 sq in).
2" PVC Fill
99 #12 THHN (Schedule 40 PVC, 3.291 sq in).
2" RMC Fill
102 #12 THHN (RMC (rigid metal conduit), 3.408 sq in).
2" IMC Fill
109 #12 THHN (IMC (intermediate metal conduit), 3.63 sq in).
2" ENT Fill
99 #12 THHN (ENT (electrical nonmetallic tubing), 3.291 sq in).
Conduit Fill Chart (all sizes)
Max THHN per conduit size from #14 to 500 kcmil in one table.
Fill checks out. Will the wire reach?
Getting the conductors in the pipe is one thing. Confirm the gauge holds up over distance with the voltage drop calculator before you pull.