This beam deflection calculator finds the maximum deflection of a simply supported beam with a central point load using δ = WL³ / (48EI).
Beam Deflection Calculator
Formula
δmax = W L³ / (48 E I) (simply supported, central point load)
How to Use This Calculator
- Enter the central point load W in newtons.
- Enter the span L in metres.
- Enter Young’s modulus E in GPa and the moment of inertia I in mm⁴, then Calculate.
Worked Example
For W = 1000 N, L = 4 m, E = 200 GPa, I = 4×107 mm⁴: δ = WL³/(48EI) ≈ 0.167 mm.
Frequently Asked Questions
What is the formula for maximum beam deflection?
For a simply supported beam with a central point load, the maximum deflection is W x L cubed divided by (48 x E x I).
Where does maximum deflection occur?
For a central point load on a simply supported beam, the maximum deflection occurs at the midspan.
What is EI in beam deflection?
EI is the flexural rigidity of the beam: E is the Young’s modulus and I is the second moment of area; a higher EI means less deflection.