Beam Deflection Calculator

The span in metres: the free length of a cantilever, or the distance between supports. Deflection grows with roughly the cube of this, so span dominates everything else.

A single concentrated force in newtons, applied at the free end (cantilever) or at mid-span (simply supported). 1000 N is about 100 kg of weight.

A load spread evenly along the beam, in newtons per metre of length — self-weight, snow, or books on a shelf.

How stiff the material itself is. Doubling E halves the deflection; the values in the hint cover the common structural materials.

How stiff the cross-section shape is, in cm⁴. Depth matters most: for a rectangle I = b·h³/12, so doubling the height gives 8× the stiffness.