Hanger spacing calculator
Estimate maximum hanger spacing and a hanger count for a horizontal run, including extras near elbows and intersections. Spacing and rod defaults live in a small data file you can check against the shop book.
Enter the run and estimate hanger count from spacing plus extras.
Spacing bands and fitting extras, not a copied table.
Regular hangers sit at both ends of the run and at the maximum spacing for the size and shape. Extra hangers are added when an estimated elbow is more than 2 ft from an existing hanger, or an estimated tee is more than 4 ft away. Fittings are treated as evenly spaced along the run so extras that land on a regular station are not counted twice.
- Does not apply an insulation allowance
- Does not size strap, trapeze, or inserts
- Does not cover risers, seismic, or point loads
- Does not replace the SMACNA HVAC DCS or the spec
Verify hanger spacing, rod or strap size, and extra supports against the current SMACNA HVAC Duct Construction Standards (Metal and Flexible) and the job spec before fabrication or installation. This calculator is a layout aid, not a fabrication release.