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NEC Chapter 9 Tables 1, 4 & 5 • NEC 310.15(C)(1)33 Verified Raceway Configurations

Conduit Fill Capacity & Maximum Wire Count Matrix

Eliminate conductor pulling friction jams and pass electrical inspections. Select your conduit trade size and wire gauge below to get the exact maximum allowable conductors under the NEC 40% fill rule, ampacity derating adjustment factors, and jam ratios.

Custom Multi-Wire Conduit Engine

Electrical Metallic Tubing (EMT) • Thin-Wall Conduit

Standard commercial and residential indoor metal raceway (NEC Chapter 9 Table 4)

1/2" EMT • #14 AWG THHN
Max Wires (40%):12 Wires
Actual Fill:38.3%
Usable 40% Area:0.122 sq in
Ampacity Derating:50%
NEC Ch. 9 CompliantView Schedule →
1/2" EMT • #12 AWG THHN
Max Wires (40%):9 Wires
Actual Fill:39.4%
Usable 40% Area:0.122 sq in
Ampacity Derating:70%
NEC Ch. 9 CompliantView Schedule →
1/2" EMT • #10 AWG THHN
Max Wires (40%):5 Wires
Actual Fill:34.7%
Usable 40% Area:0.122 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
3/4" EMT • #14 AWG THHN
Max Wires (40%):21 Wires
Actual Fill:38.2%
Usable 40% Area:0.213 sq in
Ampacity Derating:45%
NEC Ch. 9 CompliantView Schedule →
3/4" EMT • #12 AWG THHN
Max Wires (40%):16 Wires
Actual Fill:39.9%
Usable 40% Area:0.213 sq in
Ampacity Derating:50%
NEC Ch. 9 CompliantView Schedule →
3/4" EMT • #10 AWG THHN
Max Wires (40%):10 Wires
Actual Fill:39.6%
Usable 40% Area:0.213 sq in
Ampacity Derating:50%
NEC Ch. 9 CompliantView Schedule →
3/4" EMT • #8 AWG THHN
Max Wires (40%):5 Wires
Actual Fill:34.3%
Usable 40% Area:0.213 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
3/4" EMT • #6 AWG THHN
Max Wires (40%):4 Wires
Actual Fill:38%
Usable 40% Area:0.213 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
1" EMT • #12 AWG THHN
Max Wires (40%):26 Wires
Actual Fill:40%
Usable 40% Area:0.346 sq in
Ampacity Derating:45%
NEC Ch. 9 CompliantView Schedule →
1" EMT • #10 AWG THHN
Max Wires (40%):16 Wires
Actual Fill:39.1%
Usable 40% Area:0.346 sq in
Ampacity Derating:50%
NEC Ch. 9 CompliantView Schedule →
1" EMT • #8 AWG THHN
Max Wires (40%):9 Wires
Actual Fill:38.1%
Usable 40% Area:0.346 sq in
Ampacity Derating:70%
NEC Ch. 9 CompliantView Schedule →
1" EMT • #6 AWG THHN
Max Wires (40%):6 Wires
Actual Fill:35.2%
Usable 40% Area:0.346 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
1" EMT • #4 AWG THHN
Max Wires (40%):4 Wires
Actual Fill:38.1%
Usable 40% Area:0.346 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
1" EMT • #2 AWG THHN
Max Wires (40%):2 Wires
Actual Fill:26.8%
Usable 40% Area:0.346 sq in
Ampacity Derating:100%
NEC Ch. 9 CompliantView Schedule →
1-1/4" EMT • #6 AWG THHN
Max Wires (40%):11 Wires
Actual Fill:37.3%
Usable 40% Area:0.598 sq in
Ampacity Derating:50%
NEC Ch. 9 CompliantView Schedule →
1-1/4" EMT • #4 AWG THHN
Max Wires (40%):7 Wires
Actual Fill:38.6%
Usable 40% Area:0.598 sq in
Ampacity Derating:70%
NEC Ch. 9 CompliantView Schedule →
1-1/4" EMT • #3 AWG THHN
Max Wires (40%):6 Wires
Actual Fill:39%
Usable 40% Area:0.598 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
1-1/4" EMT • #2 AWG THHN
Max Wires (40%):5 Wires
Actual Fill:38.7%
Usable 40% Area:0.598 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
1-1/4" EMT • 1/0 AWG THHN
Max Wires (40%):3 Wires
Actual Fill:37.2%
Usable 40% Area:0.598 sq in
Ampacity Derating:100%
NEC Ch. 9 CompliantView Schedule →
1-1/2" EMT • #4 AWG THHN
Max Wires (40%):9 Wires
Actual Fill:36.4%
Usable 40% Area:0.814 sq in
Ampacity Derating:70%
NEC Ch. 9 CompliantView Schedule →
1-1/2" EMT • #2 AWG THHN
Max Wires (40%):7 Wires
Actual Fill:39.8%
Usable 40% Area:0.814 sq in
Ampacity Derating:70%
NEC Ch. 9 CompliantView Schedule →
1-1/2" EMT • 1/0 AWG THHN
Max Wires (40%):4 Wires
Actual Fill:36.4%
Usable 40% Area:0.814 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →
1-1/2" EMT • 2/0 AWG THHN
Max Wires (40%):3 Wires
Actual Fill:32.8%
Usable 40% Area:0.814 sq in
Ampacity Derating:100%
NEC Ch. 9 CompliantView Schedule →
2" EMT • #2 AWG THHN
Max Wires (40%):11 Wires
Actual Fill:38%
Usable 40% Area:1.342 sq in
Ampacity Derating:50%
NEC Ch. 9 CompliantView Schedule →
2" EMT • 1/0 AWG THHN
Max Wires (40%):7 Wires
Actual Fill:38.7%
Usable 40% Area:1.342 sq in
Ampacity Derating:70%
NEC Ch. 9 CompliantView Schedule →
2" EMT • 4/0 AWG THHN
Max Wires (40%):4 Wires
Actual Fill:38.6%
Usable 40% Area:1.342 sq in
Ampacity Derating:80%
NEC Ch. 9 CompliantView Schedule →

Rigid PVC Conduit (Schedule 40) • Underground & Wet Locations

Heavy-wall non-metallic conduit with slightly thicker walls than EMT

1/2" PVC • #12 AWG THHN
Max Wires (40%):8 Wires
Actual Fill:37.3%
Usable 40% Area:0.114 sq in
Ampacity Derating:70%
Direct Burial RatedView Schedule →
3/4" PVC • #12 AWG THHN
Max Wires (40%):15 Wires
Actual Fill:39.3%
Usable 40% Area:0.203 sq in
Ampacity Derating:50%
Direct Burial RatedView Schedule →
3/4" PVC • #10 AWG THHN
Max Wires (40%):9 Wires
Actual Fill:37.4%
Usable 40% Area:0.203 sq in
Ampacity Derating:70%
Direct Burial RatedView Schedule →
3/4" PVC • #8 AWG THHN
Max Wires (40%):5 Wires
Actual Fill:36%
Usable 40% Area:0.203 sq in
Ampacity Derating:80%
Direct Burial RatedView Schedule →
1" PVC • #6 AWG THHN
Max Wires (40%):6 Wires
Actual Fill:36.6%
Usable 40% Area:0.333 sq in
Ampacity Derating:80%
Direct Burial RatedView Schedule →
1-1/4" PVC • #2 AWG THHN
Max Wires (40%):5 Wires
Actual Fill:39.8%
Usable 40% Area:0.581 sq in
Ampacity Derating:80%
Direct Burial RatedView Schedule →
2" PVC • 4/0 AWG THHN
Max Wires (40%):4 Wires
Actual Fill:39.3%
Usable 40% Area:1.316 sq in
Ampacity Derating:80%
Direct Burial RatedView Schedule →