All calculators
Every duct tool and reference table on the site. Start typing to filter by name, keyword or category — search for a shape, a standard, or the thing you are trying to work out.
Duct Fitting Loss CalculatorElbow, tee and damper losses from loss coefficients, plus the straight run.Duct Velocity CalculatorAir velocity from flow and duct size — or airflow from velocity — with the band flagged.Duct Weight CalculatorSheet metal weight and surface area per metre and for the whole run.DuctulatorEqual friction and velocity duct sizing, with every intermediate value shown.Fabric Duct CalculatorNewMinimum fabric duct diameter from airflow and allowable inlet velocity.Flex Duct CalculatorNewFlex duct friction with a measured compression correction, sized as installed.Kitchen Exhaust Duct CalculatorNewGrease duct size from hood airflow, checked against the velocity window.Rectangular to Round Duct ConverterHuebscher equivalent diameter, both directions, with aspect ratio checks.
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.