About this calculator

Compare the bottom-box load in one aligned vertical column with measured box compression test (BCT) strength divided by an entered factor. The tool counts only the boxes above the bottom box plus any additional top load.

Inputs

How to use this calculator

Stack scenario

  1. Measured box compression strength (BCT) (lb)Prefer a laboratory-tested BCT for the actual box and environment.
  2. Gross weight per box (lb)Include contents and packaging.
  3. Boxes high in one aligned columnWhole tiers; this model assumes a vertical single-box column.
  4. Additional load above the top box (lb)Enter any measured external load transmitted through the same column.
  5. Entered safety factorUse a factor selected for the actual packaging and storage conditions.
  6. Box height (in)Vertical box dimension for this aligned column.
  7. Pallet height (in)Added once to total stack height.

Enter the shipment or scenario values, then select Calculate result.

Method

Formula and variables

Bottom-box demand = gross box weight × (tiers − 1) + additional top load. Allowable demand = measured BCT ÷ entered safety factor. Maximum column tiers = floor((allowable demand − top load) ÷ gross box weight) + 1, bounded at zero.

Measured box compression strength (BCT) (lb)
Prefer a laboratory-tested BCT for the actual box and environment.
Gross weight per box (lb)
Include contents and packaging.
Boxes high in one aligned column
Whole tiers; this model assumes a vertical single-box column.
Additional load above the top box (lb)
Enter any measured external load transmitted through the same column.
Entered safety factor
Use a factor selected for the actual packaging and storage conditions.
Box height (in)
Vertical box dimension for this aligned column.
Pallet height (in)
Added once to total stack height.

Interpret the result

A within-limit result applies to the entered column model. Environmental strength loss, misalignment and pallet support are not predicted by the numeric factor.

Outputs: Requested stack load, allowable load and estimated tiers

One aligned vertical column only. The user supplies actual BCT and safety factor. This does not predict strength loss from humidity, time, load pattern, pallet support, misalignment, vibration or damage; it does not certify a warehouse stack or packaging design.

Worked example

Check the arithmetic

This example uses the starting values shown above. The arithmetic below is calculated independently of the interactive result.

Work through the calculation

  1. Bottom-box demand = 32 × (10 − 1) + 0 = 288 lb.
  2. Allowable demand = 1,200 ÷ 4 = 300 lb; 288 ≤ 300.
  3. Maximum tiers = floor(300 ÷ 32) + 1 = 10; stack height = 10 × 8 + 6 = 86 in.

Compare the displayed result

Expected displayed result: Within entered load limit

FAQs

Why are tiers reduced by one when calculating bottom-box demand?

The bottom box supports the boxes above it. Its own gross weight is not an additional compression load placed on its top in this model.

Example inputs and options

Starting values are examples unless a field identifies a dated rule. Unit selectors convert only fields marked for conversion. Rates and model options keep the units and basis shown in their labels.

Measured box compression strength (BCT) (lb)
Example: 1200
Gross weight per box (lb)
Example: 32
Boxes high in one aligned column
Example: 10
Additional load above the top box (lb)
Example: 0
Entered safety factor
Example: 4
Box height (in)
Example: 8
Pallet height (in)
Example: 6