Calculate approximate elastic deflection of a steel beam from its span, cross-section, support condition and applied load.
P = point load, w = uniform load per unit length, L = span, E = Young's modulus and I = second moment of area.
What is beam deflection? Beam deflection is the displacement of a beam from its original position when subjected to load. It is commonly checked as a serviceability condition.
What is I in the beam equation? I is the second moment of area of the beam cross-section about its bending axis. It is usually expressed in mm⁴, cm⁴, m⁴ or in⁴.
Why is I so important? A section with more material positioned farther from the neutral axis can have a much larger second moment of area and therefore substantially greater bending stiffness.
Can I calculate a cantilever? Yes. Select either cantilever point loading or cantilever uniformly distributed loading.
Does a longer beam deflect more? Yes. Span has a very strong effect on deflection. Depending on the loading case, common formulas contain L³ or L⁴.
What is the difference between point load and UDL? A point load acts at a specific location, while a uniformly distributed load is spread continuously along the beam.
Does this calculator check beam strength? It provides a preliminary bending-stress indicator only when section modulus is supplied or estimated. It does not replace a complete strength and stability design.
Can this select an I-beam size? No. Beam selection requires the actual section properties, loads, support conditions, material grade and applicable design requirements.
Can I use this for a building beam? Use it only as an educational estimate. Structural members require professional design checks for all relevant load combinations and failure modes.