Duct Slide Calculation Slide Rule

American Conditioning Contractors of America Auxiliary Calculations Duct Calculator. This durable two-sided plastic sizing wheel comes with a complete instruction manual for residential and commercial duct-sizing procedures. Designed by Hank Rutkowski.


  • Sizes metal ducts, lined metal ducts, duct board airways, and wire helix flexible ducts
  • Converts round shapes to equivalent rectangular shapes
  • Correlates available pressure with total effective length and friction rate (Manual D sizing calculations)
  • Converts velocity into velocity pressure and vice versa
  • Corrects for altitude and temperature
  • $62.44