Work out column buckling capacity instantly with clear inputs, formula shown and shareable results.
A compression member fails either by crushing at the squash load, area times yield strength, or by buckling at the Euler load, pi² E I / Le², whichever is lower. Real columns fail below both because of initial curvature and residual stress, so a safety factor of about 1.67 is applied to the governing value.
Euler load
Pcr = pi² E I / Le², with I = A r²
Capacity
Design capacity = min(Pcr, A fy) / 1.67
Preliminary estimate only. Compression member design must be verified by a qualified structural engineer using the code buckling curves and section classification.
Pcr = pi² E I / Le², with I = A r². A compression member fails either by crushing at the squash load, area times yield strength, or by buckling at the Euler load, pi² E I / Le², whichever is lower.
Initial out-of-straightness, residual rolling stresses and load eccentricity all start bending before the theoretical critical load, which is why codes use empirical buckling curves rather than the Euler formula alone.
This calculator takes 4 inputs: Cross-sectional area, Radius of gyration, Effective length, Yield strength. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.