Air Purifier Room Size Calculator for Bedroom
Enter your room dimensions to find the minimum CADR you need — based on AHAM's 4.8 air changes per hour standard.
Finding the right air purifier size for your bedroom is critical — you spend 7–9 hours there every night, breathing the same air on repeat. An undersized unit won't keep up with dust mites, pollen, or pet dander that accumulates in bedding and carpet. An oversized one wastes energy and money.
The gold standard is AHAM's recommendation of 4.8 air changes per hour (ACH). For a typical 12×12 ft bedroom (144 sq ft), that means you need a purifier with a minimum CADR of about 93 CFM. Master bedrooms at 15×12 ft (180 sq ft) need roughly 116 CFM.
Use the calculator below to find your exact number. Then check our recommended bedroom purifiers — we've tested noise levels specifically, since a loud machine will ruin your sleep even if the air is spotless.
Air Changes Per Hour (ACH) Reference
| Purifier CADR | ACH for Your Room | Rating |
|---|
💡 Tips for Bedroom Air Purifiers
- ✓ Place the purifier 3–5 feet from your bed, at pillow height if possible.
- ✓ Run it on the lowest (quietest) setting overnight — most quality units clean effectively on low.
- ✓ If you have allergies, choose a unit with a True HEPA (H13) filter and change it every 6–8 months.
- ✓ Avoid placing the purifier behind curtains or in corners — it needs clear airflow on all sides.
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