STRUCTURAL
Column Size Calculator
Axial load · Biaxial bending · Slenderness · Reinforcement · IS 456
Pu
Mux
Muy
Load & geometry
kN
m
grade
grade
%
Required area (Ag)
—
mm²
Minimum dimension
—
mm
Steel area (Asc)
—
mm²
Load capacity
—
kN
Pu = 0.4 fck Ac + 0.67 fy Asc
Column cross-section
Rectangular column with longitudinal reinforcement
Load capacity
Contribution of concrete vs steel
Column design parameters
kN
kN·m
kN·m
mm
mm
grade
grade
%
Design capacity (Pd)
—
kN
Status
—
—
Steel area (Asc)
—
mm²
Min. steel bars
—
nos
Slenderness ratio
—
—
Pu ≤ 0.4 fck Ac + 0.67 fy Asc
Interaction diagram
P-M interaction curve — design point must be inside envelope
Design summary
Column size
300 × 400
mm
Load ratio
—
%
Steel ratio
—
%
Classification
—
—
Section properties
mm
mm
mm
mm
nos
mm
Area of steel (Asc)
—
mm²
Steel ratio (p)
—
%
Concrete area (Ac)
—
mm²
Gross area (Ag)
—
mm²
Tie spacing
—
mm
Asc = n × π/4 × d² | p = Asc / Ag × 100
Reinforcement layout
Typical column reinforcement arrangement
Section compliance
Min steel (0.8%)
✓
Max steel (6%)
✓
Min ties
✓
Spacing OK
✓