Conduit Size Calculator – Electrical Conduit Sizing
Calculate electrical conduit size based on wire gauge and count
Table of Contents
How to Use
- Select your wire gauge (AWG size)
- Enter the number of wires
- Choose conduit type (PVC, EMT, or Rigid)
- View the recommended conduit size
Understanding Conduit Sizing
The National Electrical Code (NEC) requires that conduits not be filled beyond 40% of their cross-sectional area when containing three or more conductors. This ensures adequate space for heat dissipation and wire pulling.
Types of Electrical Conduit
- PVC (Schedule 40): Lightweight, corrosion-resistant, suitable for underground and outdoor use
- EMT (Electrical Metallic Tubing): Thin-walled steel, common for indoor residential and commercial applications
- Rigid Metal Conduit: Heavy-duty steel, provides maximum protection for hazardous or high-traffic areas
Frequently Asked Questions
- What is the NEC conduit fill requirement?
- The NEC requires that conduits containing three or more conductors not exceed 40% fill of the conduit's cross-sectional area. For one or two conductors, the limit is 53% and 31% respectively.
- Should I use the minimum or recommended size?
- While the minimum size meets code requirements, the recommended size (usually one size larger) makes wire pulling easier and provides better heat dissipation, especially for longer runs.