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McKee Formula BCT Calculator

Estimate the Box Compression Test (BCT) strength of a standard Regular Slotted Carton (RSC) using the simplified McKee formula. This provides a baseline static strength under lab conditions.

Input Parameters (Imperial)

Standard values: 23, 32, 44, 48, 51
Example: C-Flute ≈ 0.156"
Estimated BCT (Static Lab Strength)
lbs
Perimeter: inches

Formula Details

BCT = 5.874 × ECT × (Caliper × Perimeter)0.5

Assumptions & Limitations:

  • Only valid for Regular Slotted Cartons (RSC).
  • Assumes standard lab conditions (73°F / 50% RH).
  • Does not account for humidity degradation, pallet overhang, or vibration fatigue.
  • Perimeter must not be excessively long relative to width (ratio < 3:1).

Applying a Safety Factor

Static BCT is just the starting point. To determine the actual weight a box can support in transit, divide the BCT by an environmental safety factor.

Condition Multiplier
Ideal (Lab, short duration) 2.5 - 3.0
Average (Standard domestic) 4.0 - 5.0
Severe (High humidity, export) 6.0 - 8.0