2023 NEC CH. 9 TABLE 1 CH. 9 TABLE 4 CH. 9 TABLE 5
01 Conduit
02 Calculation Mode
03 Conductors
04 Notes

NEC Table 1 applies to complete conduit systems. Actual dimensions from Table 5 are worst-case stranded values.

This tool checks physical conduit fill only. Verify ampacity separately per NEC Article 310.

Conduit Fill Summary
Total Conductor Area—
Conduit Internal Area—
Fill Percentage—
NEC Limit—
Status —
Recommended Minimum Size: —
Calculation Breakdown
TypeSizeQtyArea Each (sq in)Area Total (sq in)Formula

Fill % = (Σ(Area × Qty) / Conduit Area) × 100

Reference Tables — NEC Chapter 9

Table 4: Conduit Internal Areas

Table 5: Conductor Areas