top of page

Duct Size Calculator

Note: Duct Dimensions are always Inner Dimensions

load calc.jpg
air mixing.jpg

Adicot, Inc.'s online duct size calculator helps you determine the optimal size for your ductwork, ensuring maximum airflow and efficiency. Input your measurements and receive instant results for an easy and accurate solution. Try Adicot's duct size calculator today and improve your HVAC system's performance.


  1. Select English or Metric Units

  2. Select Material Type:

    • Duct board

    • Fabric DurkeeSox

    • Flex​

    • Metal
      Note, the button next to the selection field will bring you to a specification sheet for the material type you selected

  3. Enter the air volume in CFM [l/s]

  4. Select input criteria and enter the value:

    • Air Velocity, FPM [m/s]​​

    • Friction loss, in w.g. /100' [Pa/30m]

    • Round duct diameter, in [cm]

    • Rectangular duct dimensions, in. [cm]

  5. Optional: Enter a constraining rectangular duct dimension, in [cm]

  6. Click the Calculate button

  7. The results are displayed in the results table.

bottom of page