Shelf Sag, Support Spacing & Thickness Scenario Planner
Convert equal support count into unsupported segment span, estimate elastic and planning sag, and compare one extra support with a thicker shelf without claiming fastener capacity.
Will this shelf visibly sag between the planned supports?
For equal supports at both ends, use shelf length divided by support intervals—not the full length—as the governing span. Compare the planning sag with a visible-deflection reference, while keeping wall fixings and structural safety as separate unknowns.
Method
The engine uses rectangular-section inertia and standard simply supported uniform or centre-load beam equations. Material E and the planning multiplier stay editable because real boards, moisture, defects and long-term behaviour vary.
Important limitation
This is an appearance-deflection screen, not a strength, bracket, anchor, wall, seismic or overhead-load approval. Use actual graded/product data and have critical or injury-risk shelving reviewed by a qualified professional.
What the result cannot know
This is an appearance-deflection screen, not a strength, bracket, anchor, wall, seismic or overhead-load approval. Use actual graded/product data and have critical or injury-risk shelving reviewed by a qualified professional.
