Enter the moment and the section modulus into the calculator to determine the modulus of rupture. The modulus of rupture is a measure of the tensile strength of a material and can be calculated when the moment and section modulus are known.

Modulus Of Rupture Formula

The following formula is used to calculate the modulus of rupture.

MOR = M / S


  • MOR is the modulus of rupture (psi)
  • M is the moment (lb*ft)
  • S is the section modulus (in^3)

To calculate the modulus of rupture, divide the moment by the section modulus.

What is Modulus Of Rupture?

The modulus of rupture (MOR) is a measure of the extreme fiber stress at failure during a bending test. It is an important property for materials that are subject to bending loads, such as beams and slabs. The MOR is used to determine the load at which a material will fail in bending. It is a critical value for engineers and designers when selecting materials for construction and manufacturing applications.

How to Calculate Modulus Of Rupture?

The following steps outline how to calculate the Modulus Of Rupture.

  1. First, determine the moment (M) in pound-feet (lb*ft).
  2. Next, determine the section modulus (S) in cubic inches (in^3).
  3. Next, gather the formula from above = MOR = M / S.
  4. Finally, calculate the Modulus Of Rupture (MOR) in pounds per square inch (psi).
  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.

Moment (M) = 120 lb*ft

Section Modulus (S) = 8 in^3