The plastic section modulus is calculated as the sum of the areas of the cross section on either side of the PNA, each multiplied by the distance from their respective local centroids to the PNA.

Equations for the section moduli of common shapes are given below. There are two types of section moduli, the elastic section modulus (S) and the plastic section modulus (Z).

Use this tool to calculate the section modulus, second area moment, and neutral axis of many structural profiles, given their dimensions.

The plastic section modulus is necessary to calculate plastic moment capacity of the section. The plastic section modulus is the sum of moment of area of area under compression about PNA (plastic neutral …

Oct 5, 2025 · Engineers use the plastic section modulus to determine the maximum bending moment a beam can withstand. This value is the plastic moment capacity (Mp) and is calculated with the …

For common shapes like rectangles, I-beams, or channels, the plastic section modulus can be calculated using standardized formulas based on the geometry of the cross-section.

Mar 13, 2018 · If A C and A T are the areas of the cross section under compression and under tension respectively, and d C and d T are the distances from the centroids of the areas under compression …

Jan 5, 2025 · How do you calculate the section modulus? The Section modulus S is calculated by dividing the Moment of Inertia I by the distance z from the Cross-section centre to the edge.

Calculate section modulus for common shapes and learn more about this important cross-section property with this helpful guide.

Dec 30, 2025 · Select a shape tab, then enter the required section dimensions into the calculator to determine the plastic modulus of a cross-section.