Bending Stress Calculator

Calculate elastic bending stress from bending moment, second moment of area and distance to the extreme fibre using the flexure equation.

Bending stress σ
31.25 MPa
Section modulus Z
800000 mm³
Formula: σ = Mc/I = M/Z. Compare the calculated stress with the applicable design strength after code-required partial factors, buckling, section classification and load combinations.

When this calculator is appropriate

Use it for preliminary elastic stress checks of beams in simple bending. Do not use it alone for reinforced concrete design, plastic design, composite sections, unsymmetrical bending, local buckling or members with significant axial force.

Formula guide

Bending Stress Formula

Learn σ = My/I, the section-modulus form, consistent units, worked examples and common calculation mistakes.

Read formula