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Conduit Fill Calculator

Calculate conduit fill percentage per NEC Article 358/Table 1 standards. Add wires, select conduit type and size — instantly check code compliance.

Conduit Selection

Choose conduit type and trade size

Wire / Conductor List

Add each wire type and quantity to calculate fill area

#
Wire Type
AWG / Size
Qty
Area (in²)
Fill Percentage
of conduit capacity
NEC Status
Not Calculated
Enter wires to check compliance
Wire Area Used
in²
Conduit Area
in² internal
Remaining Space
in² available

THHN/THWN Wire Cross-Section Areas (NEC Annex C)

AWG / kcmil Area (in²) Diameter (in) Common Use