Beam Deflection Calculator
Calculate deflection for various metal profiles
Our free online beam deflection calculator helps engineers, designers, and fabricators quickly determine how much a beam will bend under load. Understanding beam deflection is crucial for structural integrity, safety compliance, and optimal material selection in construction and manufacturing projects.
Frequently Asked Questions
What is a beam deflection calculator?
A beam deflection calculator is a tool that calculates how much a beam bends under load. It considers the beam's material, cross-section, length, and support conditions to determine maximum deflection and stress.
What is the difference between deflection and deformation?
Deflection specifically refers to the transverse displacement of a beam perpendicular to its original axis, measured in millimeters. Deformation is a broader term that includes all types of shape changes — bending, stretching, twisting, and shearing. In beam analysis, we primarily calculate deflection (bending displacement) and verify it stays within serviceability limits like L/360.
Why is L/360 the standard deflection limit?
The L/360 limit comes from building codes (Eurocode EN 1993, AISC Steel Construction Manual) and represents the maximum deflection that prevents visible sagging, cracking of attached finishes like plaster, and ensures occupant comfort. For sensitive applications like laboratory floors, tighter limits of L/480 or L/600 may be required. Industrial structures may allow L/240.
How does support type affect beam deflection?
Support conditions dramatically affect deflection. For the same span, section and material, with a point load at midspan (at the tip for a cantilever): a simply supported beam deflects δ = PL³/48EI, a fixed-fixed beam δ = PL³/192EI — 4× less than simply supported — and a cantilever δ = PL³/3EI, which is 16× the simply supported value and 64× the fixed-fixed value. Fixed-fixed beams are stiffest because end fixity introduces negative moments that counteract load-induced bending. Simply supported beams are the most common in practice due to simpler connections. Source: Roark's Formulas for Stress and Strain.
What materials are supported?
We support aluminium, steel, stainless steel, brass, copper, bronze, and plastics. Each category includes multiple alloys with accurate density and elastic modulus values.
How accurate are the calculations?
Our calculators use standard engineering formulas and material properties from industry databases. Results are suitable for preliminary design and estimation purposes.
Related guides
- What Size Steel Beam Do I Need? A Quick Span Guide
- Understanding Steel Beam Deflection: A Complete Guide
- IPE Beam Load Capacity Table: How Much Can an IPE Carry per Span?