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Structure · Calculator

Wood Beam Span Calculator

Estimate a simply supported wood beam span from user-provided section modulus, allowable stress and line load. Use verified design values.

Project inputs

Enter your project values, then press Calculate.

How this calculator works

Estimate a simply supported wood beam span from user-provided section modulus, allowable stress and line load. Use verified design values.

for UDL: Mmax = wL²/8; L = √(8Mallow/w)
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 Wood Beam Span Calculator

1. Enter project inputs

  • Section modulus (cm³)
  • Allowable bending stress (MPa)
  • Uniform line load (kN/m)

2. Review the results

  • Bending-limited span
  • Allowable moment

3. Check the calculation

The calculator uses the following core relationship:

for UDL: Mmax = wL²/8; L = √(8Mallow/w)

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

Wood Beam Span Calculator FAQ

What does the Wood Beam Span Calculator calculate?

Estimate a simply supported wood beam span from user-provided section modulus, allowable stress and line load. Use verified design values.

What information do I need to use the Wood Beam Span Calculator?

The calculator uses inputs such as Section modulus (cm³), Allowable bending stress (MPa), and Uniform line load (kN/m). Use values from your drawings, measurements, product data, or project specifications.

How should I use the results from the Wood Beam Span Calculator?

Use outputs such as Bending-limited span, and Allowable 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.