Conduit Fill: Wire Calculator

Conduit Fill is a jobsite planning estimate for how much of a conduit’s internal area a pull will occupy. Pick EMT, PVC Schedule 40, or IMC, a trade size from ½″ to 4″, one stranded copper wire size from 14 AWG to 4/0, THHN or THWN-2, and a count from 1 to 40. The app shows fill percent and an illustrative cross-section drawn on the phone. Planning estimate from published wire/conduit geometry. Not a substitute for the electrical code or a licensed electrician. WHAT IT USES Wire diameters come from Southwire SPEC 10025 and SPEC 10000. Conduit bores use Allied/Atkore EMT nominal dimensions, Wheatland IMC nominal dimensions, and CANTEX Schedule 40 minimum bore. Areas are calculated from those diameters. Fill is wire area × count ÷ conduit internal area. Sources and assumptions are available in Settings. Only individual stranded copper wires of one size are supported. Count every wire,…