Column Buckling Calculator
Critical load, slenderness ratio, buckling analysis & beam-column interaction — AISC steel design
ASD (Allowable Stress Design) divides member capacity by a safety factor (~1.67). LRFD (Load & Resistance Factor Design) multiplies loads by factors and uses φ on capacity. Both are AISC-accepted methods — LRFD is standard for new design; ASD is common in practice and education.
Material
ksi
ksi
End Conditions
Cross Section
in
in
in
— Select Standard Pipe —
in
in
— Select Standard HSS —
in
in
in
— Select W-Shape —
in
in
in
in
Column Length
in (10 ft)
Applied Load
kips
Enter the axial compressive load to check demand vs. capacity. Leave at 0 to view the column’s critical buckling load without a demand check.
Combined Loading (Optional)
▼
Add applied moments for beam-column interaction analysis per AISC H1-1.
kip·ft
kip·ft
Default 1.0 (conservative). Max 2.3 for uniform moment.
in (defaults to column length)
kips
Column Buckling Results
Critical Buckling Load
—
Allowable Load
—
Slenderness Ratio (KL/r)
—
Critical Stress (σ_cr)
—
Combined Loading Results
Available Flexural Mcx
—
Strong axis
Available Flexural Mcy
—
Weak axis
AISC H1-1 Interaction
—
Shear D/C
—
AISC H1-1 Interaction Diagram
Column & Buckled Shape
Section Properties
Euler & Johnson Curves
Red = Euler (long columns) · Blue = Johnson (intermediate) · Dot = your column
This chart shows your column’s capacity based on its geometry and material — it is independent of applied loads. The curves plot critical stress vs. slenderness ratio (KL/r). Applied loads are checked separately against this capacity in the results above.
Learn more: Structural Steel Shapes Guide · Aluminum Alloys for Manufacturing