Enter the flagstone length (ft), the flagstone width (ft), and the flagstone thickness (ft) into the Flagstone Weight Calculator. The calculator will evaluate the Flagstone Weight. 

Flagstone Weight Formula

The following formula is used to calculate the Flagstone Weight. 

FLW = FL * FW * FT * 165


  • FLW is the Flagstone Weight (lb)
  • FL is the flagstone length (ft) 
  • FW is the flagstone width (ft) 
  • FT is the flagstone thickness (ft) 

To calculate the flagstone weight, multiply the flagstone length, width, and thickness, then multiply by 165, or the density.

How to Calculate Flagstone Weight?

The following steps outline how to calculate the Flagstone Weight.

  1. First, determine the flagstone length (ft).
  2. Next, determine the flagstone width (ft). 
  3. Next, determine the flagstone thickness (ft). 
  4. Next, gather the formula from above = FLW = FL * FW * FT * 165.
  5. Finally, calculate the Flagstone 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.

flagstone length (ft) = 10

flagstone width (ft) = 14

flagstone thickness (ft) = 2FLW = FL * FW * FT * 165 =  ?