Box Stack Height Calculator

Box Stack Height Calculator

Avoid crushing the boxes at the bottom of your stack. This calculator applies a standard safety factor to a box's rated stacking strength to recommend a safe maximum stack height.

Safe Load = Rated Strength / Safety Factor
Max Boxes = floor(Safe Load / Weight Per Box) + 1

Example

Box rated for 600 lbs stacking strength, 30 lbs per box, safety factor of 4:

Safe Load = 150 lbs → Max safe stack: 6 boxes

Why a Safety Factor Is Built In

Manufacturer stacking ratings assume ideal, brand-new, dry conditions - real-world storage involves humidity, repeated handling, and time-based weakening of corrugated fiberboard, all of which reduce actual load-bearing capacity below the lab-tested rating.

Heaviest Boxes Go on the Bottom

Always place your heaviest, sturdiest boxes at the base of any stack and lighter or more fragile boxes on top - this calculator assumes uniform box weight, so mixed stacks should be planned with the heaviest items lowest regardless of this general limit.