NonCircular Duct to Circular Pipe Conversions 
Convert rectangular or annular crosssection to hydraulic diameter 

Hydraulic diameter calculation is mobiledevicefriendly as of October 14, 2014 Units in hydraulic diameter calculator: Numbers may be entered in any units, so long as they are consistent. [L] means length units. [L/T] means length per unit time. [L^{3}/T] means flow rate in cubic length per unit time. For instance, if b and c are cm, then area will be cm^{2}. If velocity in cm/s and area in cm^{2}, then flow rate will be cm^{3}/s.
Using our hydraulic diameter page: If you wish to determine the crosssectional geometry of a noncircular duct, you can use a) Design of Circular Liquid or Gas Pipes or b) Design of Circular Water Pipes if you know the velocity, not the flow rate (flow rate can only be converted to velocity if the actual duct area is used, not the area based on hydraulic diameter). From the hydraulic diameter output from either (a) or (b), this page can be used to determine the geometry of the duct.
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Software, Ltd. All rights reserved. August 25, 2015: Made text fields show 8 significant figures rather than 16. Calculation still uses double precision internally.

To: LMNO Engineering home page (more calculations) Design of Circular Liquid or Gas Pipes 