Simply supported beam calculator
Pin at one end, roller at the other. Set loads anywhere along the span, pick a material and section, and get reactions, shear/moment diagrams, deflection and stress. Ideal for floor beams, joists and purlins.
About this case
How to use this simply supported beam calculator
The preset is pin at A, roller at B. Set the span, then add any combination of point loads, applied moments, uniform loads, triangular loads and trapezoidal loads at any position. Spring supports can be placed anywhere, including at overhangs, to model elastic bearings.
Material and section presets cover steel, aluminum, concrete and timber; enter custom A and I for non-standard sections. Self-weight adds the beam weight as a UDL automatically.
Reading the results for a simply supported design
Reactions at A and B are the support loads for your connection design. The maximum moment (with location) drives the section modulus check: σ = M·c/I. The maximum deflection (with location) drives the serviceability check against L/360 or L/240. The diagrams are piecewise-exact — hover to read V and M at any point.
For a beam with overhangs, the maximum positive moment may be in the span and the maximum negative moment at the support; both are reported. Export the CSV for the full V/M/θ/δ tables if you need to feed them into a spreadsheet.
Common simply supported mistakes this tool helps you catch
Forgetting that an overhanging beam with a load on the overhang produces negative moment at the support (hogging), which may require top-flange bracing or a larger section. Underestimating tributary area when converting area loads to line loads. And assuming a multi-span beam can be analysed as independent simply supported spans — the interior support moments are not zero, and the continuous calculator must be used.