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Section Modulus Calculator
Find area, centroid, second moments of area and elastic section modulus for a rectangle, circle, hollow section or triangle.
How do I calculate section modulus?
Choose a basic cross-section, enter its dimensions in one consistent unit and calculate. The tool reports centroidal Ix and Iy plus elastic section moduli about the x and y axes. For a square, Ix equals Iy. Results are geometric properties only, not a structural capacity or design check.
Frequently asked questions
How do I calculate section modulus?
Choose a basic cross-section, enter its dimensions in one consistent unit and calculate. The tool reports centroidal Ix and Iy plus elastic section moduli about the x and y axes. For a square, Ix equals Iy. Results are geometric properties only, not a structural capacity or design check.
Are my dimensions uploaded?
No. The calculation runs in this browser; entered dimensions are not uploaded or saved by this tool.
What is the difference between moment of inertia and section modulus?
The second moment of area (Ix or Iy) describes how area is distributed around an axis and has units of length to the fourth power. Elastic section modulus divides that moment by the farthest distance to the section edge and has units of length cubed.
Which cross-sections can I calculate?
This simple calculator supports solid rectangles, solid circles, centered hollow rectangles, circular tubes and triangles. It does not model I-beams, channels, built-up sections, fillets, holes placed off-center or composite materials.
Can I use this to choose a beam or check if it is safe?
No. These are ideal geometric properties, not allowable stresses or load capacity. A structural check also depends on material, loads, support conditions, buckling, connections, design codes and other factors. Ask a qualified structural engineer.