Enter the roof length (ft), the roof width (ft), and the density of roofing material (lb/ft^2) into the Roof Weight Calculator. The calculator will evaluate the Roof Weight. 

Roof Weight Formula

The following formula is used to calculate the Roof Weight. 

RW = RL * RW * RD


  • RW is the Roof Weight (lbs)
  • RL is the roof length (ft) 
  • RW is the roof width (ft) 
  • RD is the density of roofing material (lb/ft^2) 

To calculate the roof weight, multiply the roof length by the width, then multiply by the weight per unit area of material used.

How to Calculate Roof Weight?

The following steps outline how to calculate the Roof Weight.

  1. First, determine the roof length (ft).
  2. Next, determine the roof width (ft). 
  3. Next, determine the density of roofing material (lb/ft^2). 
  4. Next, gather the formula from above = RW = RL * RW * RD.
  5. Finally, calculate the Roof Weight.
  6. After inserting the variables and calculating the result, check your answer with the calculator above. 

Example Problem:

Use the following variables as an example problem to test your knowledge.

roof length (ft) = 40

roof width (ft) = 50

density of roofing material (lb/ft^2) = 2.5

RW = RL * RW * RD =  ?