Air Friction + Velocity Tool

Estimate duct area and air velocity from airflow (CFM) and round or rectangular duct dimensions.

This calculator is part of the HVACTools.pro free calculator collection — built for working HVAC technicians. The interactive widget loads when the page hydrates; the content below previews related tools while it loads.

Browse all HVAC calculators · Troubleshooting workflows · HVAC guides · Tool reviews