Concrete Column

Tied rectangular column P-M interaction by strain compatibility (ACI 318-19 Ch. 22).

Strength design (LRFD): enter factored demands (Pu, Mu, Vu from your load combinations). Results follow ACI 318-19; bar areas use standard ASTM sizes. Confirm detailing (development, spacing, ties) separately.

Design diagram — updates live with your inputs

Section

Width b (in)i Column section width

Depth h (in)i Column section depth (bending direction)

Materials

Concrete f'c (psi)i

Steel fy (psi)i

Reinforcement

Cover to bar c.l. (in)i Distance to longitudinal bar centroid

Longitudinal bari

Number of barsi Total, split equally between two faces

Factored Demands

Factored axial Pu (kip)i Compression +

Factored moment Mu (kip-ft)i

ACI 318-19

Validation, assumptions & limitations Download validation report (PDF) ↗

This calculator is verified by 4 independent tests comparing its output against closed-form statics, NDS/SDPWS design-standard values and published worked examples. Full case-by-case results are in the PDF report.

Assumptions

Tied rectangular column; longitudinal bars split equally each face.
Uniaxial bending; plane sections, eps_cu = 0.003.
Es = 29,000 ksi; standard ASTM bar areas.

Limitations

Uniaxial P-M only (no biaxial Bresler check here).
Slenderness handled by the separate beam-column tool.
Detailing (tie size/spacing, splices) confirmed separately.

Results are for preliminary design and must be confirmed by a licensed engineer against the current adopted code and project-specific conditions.