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.

Like every tool on Buncha, this one runs entirely in your browser. There's no upload, no log, no record of what you've pasted or generated. Close the tab and the data is gone.

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