`dh = (2* "a" * "b" )/( "a" + "b" )`

Enter a value for all fields

The Hydraulic Diameter of Rectangular Tubes or Ducts calculator computes the hydraulic diameter based on the height and width of the duct.

INSTRUCTIONS: Choose units and enter the following:

• (a) Width of the duct
• (b) Height of the duct

Hydraulic Diameter (hd): The calculator returns the diameter in meters.  However this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The formula for the Hydraulic Diameter of Rectangular Tubes or Ducts is:

           dh= 2•a•b / (a + b)

where:

• dh = hydraulic diameter of the rectangular duct
• a = width of the duct 
• b = height of the duct