Simply Supported Beam — Centre Point Load Calculator
Deflection, max moment and reactions for a point load at midspan.
The textbook case. Doubling the span multiplies deflection by 8 — span sensitivity is cubic for point loads.
Formula
Simply Supported Beam — Centre Point Load Calculator is a free beam deflection point load 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 Simply Supported Beam — Centre Point Load Calculator
Deflection, max moment and reactions for a point load at midspan. The calculation implements δ = PL³/48EI; M = PL/4; R = P/2 (Roark's Formulas for Stress and Strain; AISC Steel Manual beam tables). The textbook case. Doubling the span multiplies deflection by 8 — span sensitivity is cubic for point loads.
How to use Simply Supported Beam — Centre Point Load Calculator
- 1Enter Point load P in kN.
- 2Enter Span L in m.
- 3Enter Elastic modulus E in GPa (Steel 200 · concrete 25–30 · timber 11 · aluminium 69).
- 4Enter Moment of inertia I in cm⁴ (ISMB 250 ≈ 5,131 cm⁴ · 230×450 RC ≈ 17,500).
- 5Read Max deflection, Max bending moment, Max reaction instantly — no submit button needed.
- 6Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Simply Supported Beam — Centre Point Load Calculator?
- ✓Implements the standard formula — δ = PL³/48EI; M = PL/4; R = P/2
- ✓Reference cited on-page: Roark's Formulas for Stress and Strain; AISC Steel Manual beam tables
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Simply Supported Beam — Centre Point Load Calculator use?+
It computes δ = PL³/48EI; M = PL/4; R = P/2, per Roark's Formulas for Stress and Strain; AISC Steel Manual beam tables. The formula is displayed under the result.
What should I keep in mind when using this calculator?+
The textbook case. Doubling the span multiplies deflection by 8 — span sensitivity is cubic for point loads.
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 Simply Supported Beam — Centre Point Load Calculator 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.
Related Engineering tools
Reynolds Number Calculator
Compute Re from density, velocity, pipe diameter and viscosity — with instant laminar/turbulent classification.
● LiveLaminar vs Turbulent Flow Classifier
Classify hydraulic-oil or process-fluid flow regime from kinematic viscosity, line velocity and tube bore.
● LiveBernoulli Equation Solver
Solve downstream pressure between two points from velocities, elevations and fluid density (ideal, lossless).
● Live