Conduit Support Spacing Calculator

Determine conduit support and strap spacing per NEC requirements for EMT, rigid, PVC, and flexible conduit.

Results

Visualization

How It Works

The NEC specifies maximum distances between conduit supports (straps, hangers, clamps) based on conduit type and size. Supports must also be placed within a specified distance of each box, fitting, or termination.

The Formula

Supports Needed = ceil(Run Length / Max Spacing) + 1

Variables

  • Max Spacing — Maximum distance between supports per NEC (varies by conduit type and size)
  • Run Length — Total length of the conduit run in feet
  • Max from Box — Maximum distance from a box or fitting to the nearest support

Example

A 30-foot EMT run: Max spacing = 10 ft. Supports = ceil(30/10) + 1 = 4 supports. First and last must be within 3 ft of boxes.

Tips

  • PVC conduit requires much more frequent support than metal conduit due to flexibility.
  • Flexible metal conduit (FMC) must be supported within 12 inches of each box.
  • Horizontal runs of EMT need supports every 10 feet regardless of size.
  • Use appropriate support hardware: straps for wall-mounted, hangers for suspended runs.