Structural Calculator

Steel Column Design Calculator

Design steel columns for combined axial compression, flexure, and shear per AISC 360-16. Multiple section types (HSS rectangular/circular, I-shapes with taper), full interaction checks, LRFD and ASD methods.

AISC 360-16 · LRFD + ASD · SI Units

What This Calculator Can Do

A complete steel column design toolset built for practicing structural engineers.

HSS Rectangular Sections

Design hollow structural section square and rectangular tubes with full slenderness and compactness checks.

HSS Circular Sections

Design round HSS pipes with D/t slenderness limits and axial-flexural interaction per AISC 360-16.

I-Shaped Sections (with Taper)

Design W-shapes and custom-built I-sections including linearly tapered webs and flanges along the column length.

Section Classification

Automatic compact / non-compact / slender element classification per AISC Table B4.1 for flexure and compression.

Compressive Strength φP_n

Design compressive strength per AISC Chapter E with flexural, torsional, and flexural-torsional buckling modes.

Flexural Capacity φM_ncx & φM_ncy

Nominal flexural strength about both principal axes per AISC Chapter F including LTB, FLB, and WLB limit states.

Shear Capacity φV_n

Design shear strength per AISC Chapter G including web shear, tension-field action, and HSS shear provisions.

Combined Interaction H1-1a / H1-1b

Unified interaction check for axial and biaxial bending per AISC Eq. H1-1a and H1-1b with automatic branch selection.

Demand-to-Capacity Ratios

Visual DCR bars for axial, major-axis bending, minor-axis bending, shear, and combined interaction.

LRFD & ASD Dual Methods

Switch between LRFD (φ factors) and ASD (Ω factors) at any point; all checks re-run instantly for both methods.

Full Section Property Calculations

Automatic I_x, I_y, r_x, r_y, S_x, S_y, Z_x, Z_y, J, and C_w with transparent formula breakdown.

2D Column Visualization

Live elevation view rendering section shape, length, and applied axial/flexural/shear loads with directional arrows.

Step-by-Step Calculation Trace

Full engineering calculation trace with equations, intermediate values, and AISC 360-16 code references.

PDF Export

Export professional calculation reports to PDF for documentation, peer review, and project submittals.

How It Works

Get from inputs to a complete steel column design in four simple steps.

Select Section & Geometry

Choose HSS rectangular, HSS circular, or I-shape (with optional taper) and enter dimensions, length, and end conditions.

Enter P_u, M_ux, M_uy

Input factored axial load, biaxial bending moments, and shear demands along with material grade (Fy, Fu, E).

Auto-Check AISC Provisions

The engine runs classification, compression, flexure, shear, and combined interaction instantly per AISC 360-16.

Export PDF

Generate a professional calculation report with all inputs, DCR summary, step-by-step trace, and visualization.

Standards & Codes

✓ AISC 360-16 — Specification for Structural Steel Buildings. All classification, strength, and interaction provisions follow the 2016 edition.
✓ LRFD & ASD Dual Methods — Load and Resistance Factor Design (φ) and Allowable Strength Design (Ω) both supported with instant switching.
✓ Chapter E — Compression Members — Flexural, torsional, and flexural-torsional buckling with elastic and inelastic regions.
✓ Chapter F — Flexural Members — Yielding, lateral-torsional buckling, flange local buckling, and web local buckling limit states.
✓ Chapter G — Shear Members — Nominal shear strength with web shear coefficient Cv and HSS shear provisions.
✓ Chapter H — Combined Forces — Interaction Equations H1-1a and H1-1b with automatic branch selection based on Pr/Pc.
✓ Table B4.1 — Width-to-Thickness Limits — Compact, non-compact, and slender element classification for compression and flexure.
✓ SI Units Throughout — All inputs and outputs in kN, kN·m, MPa, and mm for international engineering practice.