Beam Deflection Calculator

How to calculate beam deflection

1. Choose the support and load case, and enter the span and load.
2. Choose the material, or Other to enter the elastic modulus.
3. Enter the section as a rectangle or as a moment of inertia to see the deflection and bending moment.

Frequently asked questions

What deflection is acceptable?

Building codes often limit floors to span / 360 under live load and roofs to span / 240. The span / deflection figure lets you compare.

Does it check strength?

No. It gives deflection and bending moment only; check stresses and connections with the right design standard.