Air quality planning tool
Air Purifier CADR Calculator: Room Size and Air Changes
Size an air purifier from room volume and how many air changes per hour you want. Compare results to smoke CADR on product labels—not marketing superlatives.
This tool is a planning estimate, not a product rating, price quote, medical/legal/safety certification, or retailer availability check. Based on your inputs only—no live price, stock, or availability verification.
How this estimate works
Room volume is length × width × ceiling height. The tool applies a practical air-changes-per-hour target that rises for allergies, pets, or smoke, then converts that into a smoke CADR estimate. Higher noise sensitivity may mean running lower speeds—size slightly up if you need quiet overnight operation.
Your result will appear here after you submit the form.
What to check next
- Compare smoke CADR on the label—not pollen or dust numbers alone
- Check filter replacement cost and cadence
- Use the air device matcher if humidity—not particles—is the main issue
Common mistakes
- Undersizing open-plan rooms by measuring one wall only
- Expecting purifiers to fix high humidity or mold sources alone