Biax col

Long Column Design Calculator — IS 456 / SP-16 style

Enter column data, click Compute. PDF export available.

Column width, b (mm)

Column depth, D (mm) (long side)

Floor-to-floor (mm)

Unsupported length (mm) L (if different)

Effective length factor, k

Effective cover d' (mm)

Axial load Pu (kN)

Moment about major axis Mux (kN·m)

Moment about minor axis Muy (kN·m)

Concrete grade f_ck (MPa)

Steel grade f_y (MPa)

Percentage steel (Pt %) OR leave 0 to auto-calc

Designed to match the worksheet steps in your PDF

Notes

• Calculator reproduces the long-column correction method from IS456/SP-16 style worked example.
• SP-16 K1/K2 lookup uses nearest-match approximation for common d'/D and Pt/fck values.
• PDF

Results

Click Compute to see stepwise results.

Reinforcement sketch (plan & section)

If you'd like any extra checks (e.g., slender column buckling curve, chart-based interaction factors, or different tie rules), tell me and I will add them.