Airflow cluster
CFM Calculator
Calculate CFM from room volume and ACH.
How to use
Enter inside dimensions and a project-specific ACH target.
Formula
CFM = length × width × height × ACH ÷ 60
Variables
Volume is in ft³; ACH is air changes per hour; CFM is cubic feet per minute.
Example
A 20 × 15 × 8 ft room at 6 ACH needs 240 CFM.
Result interpretation
This is a volume-flow estimate, not final equipment or code selection.
FAQ
Does this set a required ventilation rate?
No. Use applicable codes and a qualified design professional.