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Box Compression Test Strength (BCT) Calculator

Estimates the BCT of a regular slotted container (RSC) for a moment with flutes positioned vertically. (Note that BCT is not stacking strength, which is the maximum load a box can handle throughout the distribution cycle.)

Reference McKee formula (simplified version)


k1 = a constant value of 5.87

ECT = edge crush value (pounds)

h = Corrugated FiberBoard (CFB) thickness (inches)

Z = box perimeter (inches) = 2 (L+W)

Edge Crush Test (ECT): (pounds/inch)

Corrugated board thickness (h): (inches)

Box length (L): (inches)

Box width (W): (inches)

Click to Calculate Box Compression Test

Box Compression Test (BCT): pounds

Notes: 1. English units are used because ECT values are typically in pounds per inch units.

2. The simplified McKee formula above provides a quick estimate that should not be used to rate the strength of an actual box. Such an estimate shall not to be used in place of testing conditioned test samples in a controlled, repeatable test environment, with calibrated instrumentation, validated machines, and trained test operators.

3. The ECT value is often provided on the BMC (Box Manufacturer's Certificate).

Box Manufacturers Certificate

If this data is not provided by your supplier, Westpak can provide testing to determine or verify this value.