Beam Deflection Calculator
Simply Supported – Uniform Load
Calculate deflection for a simply supported beam with a uniformly distributed load
Cantilever – Point Load at End
Calculate deflection for a cantilever beam with a concentrated load at the free end
Formula
Simply Supported Uniform: δ = 5wL⁴/(384EI) | Cantilever Point: δ = PL³/(3EI)
Frequently Asked Questions
What is beam deflection?
Beam deflection is the displacement of a beam from its original position when subjected to loads. It depends on the beam's length, load, material stiffness (modulus of elasticity), and cross-section (moment of inertia). Excessive deflection can cause structural problems and code violations.
What is the L/360 rule for beam deflection?
L/360 means the maximum allowable deflection is the beam span divided by 360. For a 12-foot beam, that is 0.4 inches. This is the standard limit for floor joists and beams per most building codes (IBC/IRC). Roof beams typically use L/240.
You may also need
~
Concrete Calculator
Free concrete calculator. Calculate how many bags or cubic yards of concrete you need for slabs, footings, columns, and stairs.
Everyday~
Square Footage Calculator
Free square footage calculator. Calculate area in square feet for rooms, homes, flooring, and landscaping. Supports rectangular, circular, and triangular shapes.
Everyday+
Volume Calculator
Free volume calculator. Calculate volume of a box, cylinder, sphere, and cone. Convert between gallons, liters, and cubic feet.
Math