Calculate roof weight and dead load in pounds, tons and psf from roof size, pitch, covering material, layers and sheathing, plus remaining load capacity.

Required: roof size and a roofing material below.

Pitch converts flat footprint area into true sloped roof area.

Advanced options (framing, capacity check, rafter spacing)

Roof Weight Formula

The following formula is used to calculate the Roof Weight. 

RW = RL * RW * RD

Variables:

  • 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 =  ?