Enter the duct height (in), the duct width (in), the duct length (in), and duct thickness (in) into the Duct Weight Calculator. The calculator will evaluate the Duct Weight. 

Duct Weight Formula

The following formula is used to calculate the Duct Weight. 

DW = ((2*(H+W))*L*T)*D


  • DW is the Duct Weight (lbs)
  • H is the duct height (in) 
  • W is the duct width (in) 
  • L is the duct length (in) 
  • T is the duct thickness (in)
  • D is the duct density (lbs/in^3)
    • .1 lbs/in^3 for aluminum

To calculate a duct weight, multiply the sum of the height and width by 2, multiply again by the length and thickness, then finally again by the density.

How to Calculate Duct Weight?

The following two example problems outline the steps and information needed to calculate the Duct Weight.

Example Problem #1

  1. First, determine the duct height (in).
    • The duct height (in) is calculated to be : 10.
  2. Next, determine the duct width (in).
    • The duct width (in) is measured to be: 15.
  3. Next, determine the duct length (in).
    • The duct length (in) is found to be: 200.
  4. Next, determine the duct thickness (in).
    • In this case the thickness is .25 inches.
  5. Finally, calculate the Duct Weight using the formula above: 

DW = ((2*(H+W))*L*T)*D

The values provided above are inserted into the equation below and computed.

DW = ((2*(10+15))*200*.25)*.1 = 250.00 (lbs)