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Conduit Size Calculator – Electrical Conduit Sizing

Calculate electrical conduit size based on wire gauge and count

Calculate Size

How to Use

  1. Select your wire gauge (AWG size)
  2. Enter the number of wires
  3. Choose conduit type (PVC, EMT, or Rigid)
  4. 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.

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