RC Column Calculator

Calculate reinforced concrete column capacity with M-N interaction diagram. Determine ultimate strength under combined axial load and bending — free structural tool

Column Section

b (mm) - Width

D (mm) - Depth

Fc (N/mm²) - Concrete strength

Cover (mm)

Main Reinforcement

Bar Diameter

D10D13D16D19D22D25D29D32D35D38D41

Number of Bars

Axial Load N (kN)

Section Summary

Total As

4054 mm²

Reinforcement ratio

1.23%

Effective depth d

550 mm

Section

600x600

M-N Interaction Key Points

Condition	N (kN)	M (kN·m)
Pure compression	8742.5	0.0
Balanced failure	3624.4	890.1
Pure bending	0.0	639.7
Pure tension	-1398.5	0.0

Capacity Check

Applied axial N

2000.0 kN

Ultimate moment Mu

777.8 kN·m

* Simplified calculation using SD345 rebar and equivalent stress block method

* Confinement effect of ties is not considered