Duct Calculator Elite

Duct Calculator Elite is an engineering-grade HVAC duct sizing app for iPhone and iPad. Built on ASHRAE Handbook—Fundamentals friction-loss equations, it helps HVAC professionals, mechanical engineers, and contractors size round and rectangular ducts with precision.

Use dedicated calculators for duct size by airflow, duct size by dimension, and pressure drop. Design tools calculate friction rate from static pressure and fittings, estimate airflow from heat load, and account for duct material roughness, temperature, elevation, air density, and viscosity. Results include standard duct sizes, actual friction, effective length, and pressure-drop calculations.

The app supports multiple duct dimensions, airflow, velocity, and pressure-loss units, plus a broad range of duct materials. It works fully offline with no ads, subscriptions, or account required—making it practical for design work, field calculations, and job-site use.