Duct Calculator Mobile App

Thermaflex® Duct Sizing at Your Fingertips

Thermaflex is literally at your fingertips with this convenient and easy-to-use application for iPhone and Android. This app allows HVAC installers to determine the smallest size Thermaflex duct recommended for the installation at hand, based on the project’s specific volume and friction loss. Simply select the Thermaflex product you’re installing, as well as the friction loss and volume present in the system, and the app will calculate the velocity of the system and display the appropriate size Thermaflex duct for your application.


  • Values can be selected quickly by scrolling
  • Contact page submits questions and requests directly to Thermaflex team
  • Products page presents product photos, features and specifications

This calculator uses the applicable test data in consideration of the acceptable practice of duct installation as specified in the Air Diffusion Council’s “Flexible Performance & Installation Standards” green book.