Simple Beam Deflection Calculator
Estimate elastic deflection, bending moment and bending stress for common simple beam cases.
“A 500 kg pump sits on a two-metre beam. Will the beam sag enough to affect alignment?”
Beam deflection reference
δ_max = P L³ / 48 E Iδ_max = 5 w L⁴ / 384 E Iδ_max = P L³ / 3 E Iσ = M / ZSimply supported beam with central point load
Choose the beam and load case
Start with the support condition and the load you actually know.
Tell us what section you have
You no longer need to know I and Z before using the calculator.
Choose how to compare deflection
L/500 means the allowable movement is the span divided by 500. For a 2 m span, that is 4 mm.
Elastic beam response
Span divided by calculated movement.
L/500
Elastic deflection is 5.3% of the selected L/500 comparison.
Euler-Bernoulli elastic beam formulas only. This does not check lateral-torsional buckling, local buckling, web crippling, torsion, load distribution, support flexibility, vibration, fatigue or dynamic amplification.
Save the calculation, not just the number.
Copy a permalink that reloads these inputs, or download a PDF record with inputs, visible results, assumptions, a sensitivity note, date and disclaimer.
A calculator can show the arithmetic. It cannot establish every requirement that applies.
Confirm the actual equipment, loading, materials, condition, jurisdiction, contractual requirements, standard edition and current project documentation before using the result for design, repair, testing or lifting decisions.
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