Column Design

Axial compression, stability (CP) & combined loading per NDS 3.7-3.9.

✓ Validated4 independent tests · PDF

Design diagram — updates live with your inputs

Member & Material

Material typei

Speciesi

Gradei

Standard sectioni Pick a standard size (filtered to the chosen material type) to fill d1/d2, or Custom to enter them manually

Width b (d1) (in)i

Depth d (d2) (in)i

Geometry & Supports

Unbraced height (ft)i

Ke about b-axisi Effective length factor, NDS App. G

Ke about d-axisi

Loads

Axial dead load P_D (lb)i

Axial live load P_L (lb)i

Axial snow load P_S (lb)i Roof snow to column

Moment M_D (lb-ft)i 0 for pure column

Moment M_L (lb-ft)i Combined loading -> NDS 3.9

Moment M_S (lb-ft)i Snow-induced moment (optional)

Design methodi ASD or LRFD load combinations

Load durationi

Design Assumptions

Service conditioni

Temperaturei

Incised lumberi Yes

NDS 2018 / SDPWS 2015

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

Concentric axial load, pinned-pinned (Ke=1.0), c=0.8 (sawn).
Square 6x6 (5.5x5.5); reference values NDS Supplement Table 4A.
Dry/normal service; no applied moment (pure column).

Limitations

Combined axial+bending (NDS 3.9-3) is covered by the Stud Wall tool.
Buckling about the weak axis only when unbraced; biaxial not separated here.

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