CNC Dust Collection CFM Calculator
Dust collection airflow for a CNC router or mill.
Enter your values
ⓘ Live results
Results
- Required airflow
- 349 CFM
- Per port
- 349 CFM
- Transport velocity used
- 4,000 FPM
- Collector filter area
- 43.6 sq ft (at 8:1 air-to-cloth)
Quick answer
A CNC router typically needs 350-800 CFM at the hood depending on spindle size and enclosure, delivered at 3500-4500 FPM in the hose for chip transport.
CFM = port area x transport velocity
How to use the CNC Dust Collection CFM Calculator
- 1Measure the dust port diameter(s) at the CNC hood.
- 2Enter the number of ports open simultaneously.
- 3Keep hose velocity at 3500-4500 FPM to keep chips moving without settling.
Worked example
Using the values the calculator loads with:
Inputs
- Dust port diameter4 in
- Active ports1
- Transport velocity4000 FPM
Results
- Required airflow349 CFM
- Per port349 CFM
- Transport velocity used4,000 FPM
- Collector filter area43.6 sq ft (at 8:1 air-to-cloth)
Frequently asked questions
Can a shop vac handle a CNC router?
Small routers with a single 2.5 in port can work with a strong shop vac, but larger routers need a real dust collector.
Why does velocity matter so much?
Below about 3500 FPM, heavier chips and dust settle in horizontal runs and eventually clog the line.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.