About

AirPurifyingSystem.com publishes free calculators for sizing air cleaning equipment — air changes per hour, CFM, air scrubber and negative air machine counts, and home air purifier CADR. Every result shows the formula behind it, so you can check the number rather than take it on trust.

The calculators are independent of any manufacturer. Some pages link to retailers through affiliate programs, which is how the site is funded; the math never changes based on which product a link points to. See the affiliate disclosure.

Found an error, or want a calculator we don't have? Email support@airpurifyingsystem.com.