Free tools
Indoor Air Calculators
Use transparent formulas and your own inputs to size equipment, estimate ownership cost and plan cleaner indoor air.
CADR / room-size calculator
Calculate the clean-air CFM target from square footage, ceiling height and desired air changes per hour.
Multi-unit sizingHow many air purifiers do I need?
Turn room volume, target ACH and one purifier's CADR into a whole-unit count and achieved air-change rate.
Ownership costAir purifier total cost calculator
Add purchase price, electricity and replacement filters to compare multi-year ownership cost.
Wildfire smokeWildfire clean air room planner
Calculate the EPA-style smoke CADR target and compare published DIY air-cleaner CADR results in your room.
Energy costDehumidifier running cost calculator
Estimate cost per day, month, humid season and year from power draw, active runtime and electricity price.