Column Buckling Calculator

A slender column under axial load can fail by suddenly bowing sideways (buckling) at a load well below what the material's strength alone would suggest it could carry. The longer and more slender the column, the lower this critical load — which is why the same steel section can safely carry a huge load as a short column but very little as a long, unbraced one.

It adjusts the actual length to an "effective" buckled length based on how the ends are restrained. A pinned-pinned column (K=1) buckles over its full length; a fixed-fixed column (K=0.5) is far stiffer because its ends can't rotate, so it behaves as if it were half as long — which is why the Euler load quadruples for the same physical length.

A very slender column buckles elastically, well before the material yields — its capacity is governed almost entirely by the Euler formula. A short, stocky column instead yields before it would ever buckle elastically, so its capacity is closer to the material's yield strength. AISC 360 blends these two behaviours with a single continuous formula (Eq. E3-2/E3-3) rather than a sharp cutover.

No — this checks pure axial (concentric) compression capacity only. A column with a bending moment as well as axial load needs a separate combined axial-bending interaction check (AISC 360 Chapter H) — the moment reduces the axial capacity available.