Steel Beam Design Calculator (AISC)

Interactive tool to calculate steel beam design parameters according to AISC standards. Designed for civil and structural engineers.

Beam inputs

How to use

Enter the beam length, uniform load, yield strength, and section modulus. Click Calculate or let live inputs trigger the update—the summary will show moment capacity, deflection, and how close the beam is to its capacity.

Methodology

Moment capacity uses \(M_c = \frac{F_y Z}{γ_m}\) with \(γ_m = 1.67\). Deflection uses the uniform-load formula \(δ = \frac{5wL^4}{384EI}\) with assumed \(E = 29,000\,ksi\) and \(I = 200\,in^4\). Applied moment for a simply supported uniformly loaded beam is \(wL^2 / 8\).

  • Length is converted to inches when computing deflection.
  • Utilization is the ratio of applied moment to nominal capacity.
  • Section modulus and yield strength are adjustable to match your profile.

Full original guide (expanded)

Data Source and Methodology

Formulas derive from the AISC Steel Construction Manual and the AISC teaching aid PDF for first-semester design examples.

The Formula Explained

Moment Capacity: \(M_c = \frac{F_y Z}{γ_m}\)

Deflection: \(δ = \frac{5 w L^4}{384 E I}\)

Glossary of Variables

  • Fy: Yield strength of the steel (ksi).
  • Z: Plastic section modulus (in³).
  • γm: Material safety factor (1.67).
  • w: Uniform load (kips/ft).
  • L: Beam length (ft).
  • E: Modulus of elasticity (29,000 ksi).
  • I: Moment of inertia (200 in⁴).

Frequently Asked Questions (FAQ)

What standards does this calculator use?

The AISC 360-16 specification.

What units are used?

US customary units (feet, kips, inches, ksi).

What safety factor is applied?

γm = 1.67 for steel beams.

Formulas

Moment Capacity: \(M_c = \frac{F_y Z}{γ_m}\)

Deflection: \(δ = \frac{5 w L^4}{384 E I}\)

Applied Moment: \(M = \frac{w L^2}{8}\)

Citations

AISC Steel Construction Manual & AISC Design Examples — https://www.aisc.org/globalassets/aisc/university-programs/teaching-aids/first-semester-design-examples.pdf

Changelog
  • 0.1.0-draft — 2026-01-19: Initial audit spec draft generated from HTML extraction.
  • Verify formulas match the calculator engine and convert text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the methodology.
Verified by Ugo Candido
Last Updated: 2026-01-19
Version 0.1.0-draft