Conduit Fill Calculator

Calculate conduit fill percentage based on wire count and size. Free, instant.

How to Use Conduit Fill Calculator

1

Enter the number of wires.

2

Enter each wire cross-section area.

3

Enter the conduit internal area.

Frequently Asked Questions

What is the NEC max conduit fill?

NEC allows 40% fill for 3+ wires, 31% for 2 wires, and 53% for 1 wire.