Airflow Unit Conversion Calculator
Enter the air velocity or volume airflow and the duct area, then select the appropriate units.
Clicking the calculate button without input will load the example below. Calculations are approximate.
Using the airflow calculator above, type the airflow value of 400 and select LFM as the units. Next type the circular duct dimensions of r = 2 in. After pressing the Calculate Airflow button, read the CFM requirement of 34.91 CFM in the volume airflow units column.