Architect Tools

Structure · Calculator

Beam Deflection Calculator

Calculate midspan deflection of a simply supported beam under a full-span uniform load.

Project inputs

Enter your project values, then press Calculate.

How this calculator works

Calculate midspan deflection of a simply supported beam under a full-span uniform load.

δmax = 5wL⁴/(384EI)
Engineering note: This calculator is for preliminary checking and education. Do not use it as the sole basis for structural design, member selection, code compliance or construction. Use applicable standards and a qualified engineer.

How to use the Beam Deflection Calculator

1. Enter project inputs

  • Beam span (m)
  • Uniform load (kN/m)
  • Elastic modulus (GPa)
  • Second moment of area (cm⁴)

2. Review the results

  • Maximum deflection
  • Span / deflection
  • Maximum moment

3. Check the calculation

The calculator uses the following core relationship:

δmax = 5wL⁴/(384EI)

Design note: This tool is intended for preliminary engineering checks, not final structural design or code compliance.

Beam Deflection Calculator FAQ

What does the Beam Deflection Calculator calculate?

Calculate midspan deflection of a simply supported beam under a full-span uniform load.

What information do I need to use the Beam Deflection Calculator?

The calculator uses inputs such as Beam span (m), Uniform load (kN/m), Elastic modulus (GPa), and Second moment of area (cm⁴). Use values from your drawings, measurements, product data, or project specifications.

How should I use the results from the Beam Deflection Calculator?

Use outputs such as Maximum deflection, Span / deflection, and Maximum moment for preliminary checking and comparison only. Final structural design, member selection, detailing, and code compliance should be verified by a qualified engineer using the applicable standards.