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Duct Size Calculator

Note: Duct Dimensions are always Inner Dimensions



Size supply and return air diffusers


Adicot, Inc.'s Duct Size Calculator is a versatile and powerful tool designed to assist professionals in the HVAC (Heating, Ventilation, and Air Conditioning) industry. Whether you work with metric or English units, this calculator can handle both, providing convenience and flexibility for users worldwide. Modeled after the renowned original Ductualtor by Trane, this calculator carries on the legacy of precision and accuracy in duct sizing. The user can size ducts based on different parameters. Users can input air velocity, friction factor, or duct dimensions to obtain the required duct size. This functionality enables HVAC professionals to tackle various projects, from designing new systems to evaluating existing ones. The Duct Size Calculator is an indispensable tool for various professions within the HVAC industry. Mechanical engineers, HVAC designers, contractors, and technicians can all benefit from this tool. It simplifies the complex process of duct sizing, allowing professionals to optimize airflow, ensure efficient performance, and comply with industry standards and regulations. Whether it's designing duct systems for commercial buildings, residential projects, or industrial facilities, the Duct Size Calculator offers reliable and accurate calculations, streamlining the workflow and saving valuable time and resources. With its user-friendly interface and comprehensive features, Adicot, Inc.'s Duct Size Calculator is essential for anyone involved in HVAC system design and installation. Whether working in metric or English units, professionals in the field can rely on this calculator to deliver accurate and efficient duct sizing results, enhancing their productivity and enabling them to provide top-notch HVAC solutions.


  1. Select English or Metric Units

  2. Select Material Type from the dropdown menu.  (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 an input criteria and enter its value.

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

  6. Click the Calculate button

  7. The results are displayed in the results table.

Screenshot of the Ductulator  Demonstration Video
Diffuser Size  Calculator Icon
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