Enter the plate thickness (mm) and the length of weld (mm) into the Weld Section Modulus Calculator. The calculator will evaluate the Weld Section Modulus. 

Weld Section Modulus Formula

The following two example problems outline the steps and information needed to calculate the Weld Section Modulus.

WSM = s^2*L / 6


  • WSM is the Weld Section Modulus (mm^3)
  • s is the plate thickness (mm) 
  • L is the length of weld (mm) 

To calculate the weld section modulus, square the plate thickness, then multiply by the length of weld divide by 6.

How to Calculate Weld Section Modulus?

The following steps outline how to calculate the Weld Section Modulus.

  1. First, determine the plate thickness (mm). 
  2. Next, determine the length of weld (mm). 
  3. Next, gather the formula from above = WSM = s^2*L / 6.
  4. Finally, calculate the Weld Section Modulus.
  5. 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.

plate thickness (mm) = 3

length of weld (mm) = 10

WSM = s^2*L / 6 = ?