FREE ENGINEERING TOOL · McKEE FORMULA

Box compression
strength calculator.

Estimate BCT from board grade and box dimensions, derate for real warehouse conditions, and check whether your pallet stack holds. The same first-pass math our engineers run on every spec.

Predicted BCT
—

McKee estimate of peak compression strength, as-manufactured, lab conditions.

Derated working strength
—

After environment factors and safety factor — the number you can actually stack against.

Max safe boxes per column
—

At the loaded box weight you entered, bottom box governs.

Your stack
—

SHOW THE MATH

No black box.

Enter a spec above — the full calculation appears here.
FactorConditionMultiplier
Storage timeCross-dock (<1 day)1.00
10 / 30 / 90 / 180+ days0.65 / 0.60 / 0.55 / 0.50
Humidity50 → 90% RH1.00 → 0.52
Stacking patternInterlocked vs column0.55 vs 1.00
Pallet overhangAny edge overhang0.68

Method: simplified McKee formula, BCT = 5.87 × ECT × √(caliper × perimeter), with derating multipliers in the ranges published by the Fibre Box Handbook and TAPPI. This is a first-pass engineering estimate — it assumes standard RSC construction and does not replace physical compression testing (TAPPI T804) or ISTA transit validation. For a spec you can put a PO against, send it through and a Rox engineer will verify board grade, run samples, and quote it firm.

NEXT STEP

Get this spec verified & quoted.

Send the same dimensions and board grade through our RFQ — firm price and lead time back within 24–48 hours, reviewed by a real packaging engineer.

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