Duct Airflow Calculator for HVAC SystemsBy Karthikeyan / February 6, 2025 Unique Duct Airflow Calculator Duct Airflow Calculator Designed by TheHVACLab Select Unit: Imperial (inch, ft/min) SI (mm, m/s) Duct Type: Round Square Rectangular Oval Comparison Mode (compare all duct shapes) Insulation: Not Applicable Outside Insulation Only Inside Insulation Only Both Inside and Outside Insulation Insulation Thickness (in): Original Duct Width/Diameter (in): Original Duct Height (in): Air Density (lb/ft³): Air Velocity (ft/min): Final Duct Width/Diameter (in): Final Duct Height (in): Calculate Comparison of Duct Shapes Duct Shape Airflow (CFM) Airflow (m³/hr) Mass Flow Rate (kg/s) Mass Flow Rate (kg/hr)
