buncha/engineering/conduitfill

Conduit Fill Calculator

Conduit type

Trade size

Conductors in the run4 total

Fill

10.0%

of 40% max (4 cond.)

Passes — 0.160 sq in spare

Conductor area

0.0532 in²

Allowable area

0.2132 in²

Conduit area

0.533 in²

Conduit

EMT (steel) 3/4"

NEC Chapter 9 reference. Conduit areas from Table 4. Conductor areas from Table 5 (THHN/THWN-2 and XHHW). Maximum fill from Table 1: 53% for one conductor, 31% for two, 40% for three or more — that count includes grounds and bare conductors. This tool covers EMT, RMC, PVC Sched 40 and PVC Sched 80; FMC and LFNC get their own slightly different tables.

Read the guide

Will My Wires Fit? NEC Conduit Fill, Without the Spreadsheet

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About Conduit Fill Calculator

Will the bundle fit? NEC Chapter 9 fill % for EMT, RMC, PVC 40 and PVC 80 — with auto-upsize when it doesn't.

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