Duct Charts and Tables
Reference tables for the numbers that get looked up rather than calculated — recommended velocities by application, sheet metal gauge by pressure class, the diameters actually manufactured in each system, and a CFM-to-size chart at standard friction rates. Every table states the standard it comes from and where that standard stops applying, because a value quoted without its basis is a value nobody can defend.
Duct Friction ChartNewThe ductulator friction chart, imperial and metric, drawn from the equations.Duct Size Chart (CFM)CFM to duct size at standard friction rates, round and rectangular.Duct Velocity ChartRecommended velocities by application for mains, branches and outlets.Round to Rectangular Duct ChartNewRectangular width for every round diameter at common duct depths.SMACNA Duct Gauge ChartGauge by pressure class and duct size, with thickness in mm and inches.Standard Round Duct SizesEN 1506 metric and imperial spiral diameters with area and flow range.