CADR Calculator

Find the minimum Clean Air Delivery Rate for your room.

Length (ft)

Width (ft)

Ceiling (ft)

ACH: 4

Minimum CADR Required

240

CFM

Room: 180 sq ft · Vol: 1,440 cu ft

Dust CADR

240

CFM

Pollen CADR

240

CFM

Smoke CADR

240

CFM

🏠 Your room, to scale (top view)

180 ft² Purifier

15 ft × 12 ft floor plan · purifier placed in a corner

Filters all the air in your room 4× per hour — about once every 15 min.

That's roughly a 17 m² bedroom-sized space.

🔍 Already have a purifier? Select it below:

📐 How CADR Is Calculated

Formula: CADR = (Sq Ft × Ceiling × ACH) ÷ 60

Dust CADR = base · Pollen CADR ≈ base · Smoke CADR ≈ base × 0.9

AHAM recommends ≥ 4.8 ACH. Allergies: 6 ACH. Smoke/Asthma: 8 ACH.

Recommended Air Purifiers

Based on 240 CFM minimum Smoke CADR:

✅ Next steps

Aim for an air purifier rated at least 240 CFM (smoke CADR 216 CFM) for this room.

See matching models ↓ Take the 60-sec finder quiz → Browse buying guides →

📏 Room Size → 💰 Cost Calc → 🔄 Filter Calc → 🔍 Finder →

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Enhanced Version

Got readers who care about clean air? Drop this calculator into any page — no signup, no fees, just paste the code. Includes smart product matching from our curated air purifier database — automatically recommends the best purifiers based on your room size and CADR requirements. Database regularly updated with real noise levels, prices, and performance data. Product links go to Amazon (affiliate links) to help keep this tool free.

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