dust-collection

How to Calculate Dust Collection: 2026 CFM and Duct Guide

How to Calculate Dust Collection in 2026 To calculate dust collection, add the CFM required by the largest tool running at one time, choose duct diameter that keeps air velocity near 3,500-4,500 FPM, then subtract static-pressure losses from duct length, elbows, hose, fittings, filter, and separator. Most small woodworking shops need 400-800 CFM at the tool, while cabinet saws, planers, and jointers often need 600-1,200 CFM with 4- to 6-inch ducting. Use the Dust Collection Calculator(/crafts/dust-collection-calculator) to size your collector and duct path. The common small-shop mistake is buying by motor horsepower alone. A "2 HP" collector connected through 20 feet of flex hose, two tight elbows, a cyclone lid, and a clogged filter may deliver far less air than expected at the tool. The calculation has to happen at the machine port, not at the marketing label. If the planer needs 800 CFM and the duct path leaves only...