Section Modulus Calculator (Rectangle)
Elastic section modulus, inertia and area of a rectangular section.
Depth enters squared in S and cubed in I — turning a 50×150 plank on edge versus flat changes its strength 3× and stiffness 9×.
Formula
Section Modulus Calculator (Rectangle) is a free section modulus for structural engineers, fabricators and site engineers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Section Modulus Calculator (Rectangle)
Elastic section modulus, inertia and area of a rectangular section. The calculation implements S = bh²/6; I = bh³/12 (Any statics text; AISC/IS handbook). Depth enters squared in S and cubed in I — turning a 50×150 plank on edge versus flat changes its strength 3× and stiffness 9×.
How to use Section Modulus Calculator (Rectangle)
- 1Enter Width b in mm.
- 2Enter Depth h in mm.
- 3Read Section modulus S, Moment of inertia I, Area instantly — no submit button needed.
- 4Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Section Modulus Calculator (Rectangle)?
- ✓Implements the standard formula — S = bh²/6; I = bh³/12
- ✓Reference cited on-page: Any statics text; AISC/IS handbook
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Section Modulus Calculator (Rectangle) use?+
It computes S = bh²/6; I = bh³/12, per Any statics text; AISC/IS handbook. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Depth enters squared in S and cubed in I — turning a 50×150 plank on edge versus flat changes its strength 3× and stiffness 9×.
Can I use this for real structural design?+
It implements the exact textbook/code formula cited below the result and is ideal for sizing, checking and learning. Final designs should be verified by a qualified engineer against the full code with all load cases.
Is the Section Modulus Calculator (Rectangle) free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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