What this tool answers
You need a first-pass dust-collector airflow class before buying a single-stage bag unit for a US woodworking shop. The calculator multiplies tool CFM by a duct factor, then names the smallest class on this site’s ladder (537, 800, 1,100, or 1,550 CFM) — or returns NO_MATCH.
Why a duct factor
Nameplate CFM is usually free-air or near-free-air. Long runs, flex hose, small diameter, and Y-branches cut real capture at the tool. Concurrent machines on one collector raise demand further. Factors 1.0 / 1.25 / 1.5 are transparent screens — not a full duct-design model.
Typical tool CFM ballparks
Many hobby table saws and sanders land near 300–400 CFM at the port; larger planers and multi-machine shops need more. Always prefer the machine maker’s published requirement when available.
When the answer is NO_MATCH
If required airflow exceeds 1,550 CFM, this site returns NO_MATCH. Split machines, shorten ducts, or use a larger industrial system — do not force a 1,550 CFM consumer class.
Sources
VEVOR US dust collector product pages for 537 / 800 / 1,100 / 1,550 CFM classes (HTTP 200, 2026-09-10). Shop practice of matching free-air CFM with duct-loss margins. Complementary to ShopCFM (compressed air), not a duplicate intent.