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The airflow (CFM) each shop machine needs for effective dust capture, the minimum CFM to keep each duct size clearing, and how to size a dust collector for your largest tool. Use it as a reference, then run the numbers in our calculator.
Most stationary tools need 350–400 CFM at the machine for good dust capture — small tools like sanders and a router table around 350 CFM, planers and jointers 400–550 CFM, and large drum sanders or big cabinet saws 600+ CFM. By collector power, a 1 HP single-stage unit moves about 650–800 CFM, a 2 HP unit 1,200–1,500 CFM, and a 3 HP cyclone 1,700+ CFM. Size for your single largest machine plus duct and filter losses (pick a collector rated 1.5–2× the machine's requirement), and keep branch velocity at or above 4,000 FPM so chips don't settle in the duct.
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Minimum CFM is the airflow needed for acceptable capture; recommended CFM gives you a margin for fine dust and real-world duct losses. Values are measured at the machine's dust port. Larger or industrial versions of any tool generally need more.
| Machine / Tool | Minimum CFM | Recommended CFM | Typical Port Size |
|---|---|---|---|
| Table saw (cabinet) | 350 | 400 | 4" |
| Contractor saw | 350 | 400–450 | 4" |
| Cabinet saw + overarm guard | 400 | 550–600 | 4" + 2.5" |
| Jointer (6" / 8") | 350 | 400–450 | 4" |
| Planer (12") | 400 | 450 | 4" |
| Planer (15"+) | 450 | 550 | 4"–5" |
| Bandsaw | 350 | 400 | 4" |
| Drum sander | 550 | 600+ | 4" |
| Disc / belt sander | 350 | 400 | 4" |
| Router table | 300 | 350 | 2.5"–4" |
| Lathe | 350 | 400–500 | 4" |
| Miter saw | 350 | 550+ | 4" (+ hood) |
| Scroll saw | 150 | 250 | 2.5" |
| Drill press | 300 | 350 | 2.5"–4" |
| CNC router | 400 | 550–650 | 4" |
| Downdraft table | 400 | 600+ | 4"–6" |
| Small / benchtop sander | 300 | 350 | 2.5"–4" |
This is the minimum airflow each duct size needs to maintain a 4,000 FPM branch velocity — the speed required to keep wood chips entrained in the air instead of dropping out and clogging the line. If your collector can't deliver this CFM through a given pipe size, the duct is effectively too big.
| Duct Diameter | Minimum CFM (≥4,000 FPM) |
|---|---|
| 4" | ~350 CFM |
| 5" | ~545 CFM |
| 6" | ~785 CFM |
| 7" | ~1,070 CFM |
| 8" | ~1,400 CFM |
Note: 4,000 FPM is the standard target for horizontal branch runs carrying chips. Vertical runs and clean-air main lines can run lower (around 3,500 FPM) without dropout.
Sizing comes down to one principle: a hobby or one-man shop collects from one machine at a time, so the collector only has to satisfy your single biggest tool — plus everything the air has to fight through to get there.
These are the two numbers that define a dust collector, and they pull against each other:
Cubic feet per minute — how much air the collector moves. More CFM means more dust and chips carried away per second. It's the headline spec, but it's measured with no resistance attached.
Measured in inches of water gauge (in. w.g.) — the resistance the collector must overcome from hose, duct, elbows, and filters. Long or restrictive systems demand high static pressure; if the collector can't supply it, CFM at the tool collapses.
A unit advertising big CFM but weak static-pressure capability will look great on a 5-foot hose and disappoint on a real ducted system. When comparing collectors, check the fan curve — how much CFM survives at the static pressure your ductwork creates.
The right collector and a clean duct setup make the difference between a dusty shop and a healthy one. These are the picks we trust for matching the CFM numbers in the chart above. All links are affiliate links — we may earn a commission at no cost to you.
For a one-man shop where only a single machine runs at a time, a 1.5 to 2 HP single-stage collector moving roughly 1,000 to 1,500 CFM (rated, before duct losses) handles most stationary tools including a table saw, jointer, planer, and bandsaw. Size for your single largest machine plus ductwork losses rather than for running several tools at once. If you have a 15-inch+ planer, a wide drum sander, or long duct runs, step up to a 3 HP cyclone (1,700+ CFM) for reliable performance.
A table saw needs roughly 350 to 400 CFM at the dust port for good chip and dust capture, typically through a 4-inch port. Contractor saws with open bases can need more airflow because they leak air, while a fully enclosed cabinet saw captures dust efficiently at around 400 CFM. Adding an overarm blade-guard pickup increases the total to about 550 to 600 CFM if you collect from both the cabinet and the guard.
A 1 HP single-stage dust collector moves roughly 650 to 800 CFM and works for small shops with light-duty tools like sanders, a small bandsaw, or a benchtop planer connected by short 4-inch hose. It is generally underpowered for a full-size planer, jointer, or for any meaningful run of ductwork, where airflow drops quickly due to static pressure losses. For a shop with stationary machines, a 1.5 to 2 HP unit is a better minimum.
CFM (cubic feet per minute) measures the volume of air a collector moves, which determines how much dust and chips it can carry away. Static pressure (measured in inches of water gauge) measures the resistance the system creates from hose, ductwork, elbows, and filters, which the collector must overcome. A collector with high CFM but low static-pressure capability will lose airflow fast on long or restrictive duct runs, so both numbers matter when sizing a system.
Ductwork, flex hose, elbows, and filters all add static pressure that reduces a collector's rated airflow at the tool. Flexible hose and tight elbows are the biggest offenders, and every fitting and foot of run adds resistance. A common rule of thumb is to choose a collector rated at 1.5 to 2 times the CFM your largest machine requires so that real-world airflow at the port stays adequate after these losses. Keeping runs short, using smooth metal duct, and minimizing elbows preserves the most CFM.
A 6-inch or 8-inch jointer needs about 350 to 450 CFM, while a 12-inch planer needs around 400 CFM and a 15-inch or larger planer needs 550 CFM or more because they produce heavy, fast-moving chips. These machines benefit from a 4-inch port (5- to 6-inch on larger industrial models) and a collector with enough static pressure to keep chips moving up the duct rather than settling and clogging.