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
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)
—
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.