82 ECT vs 90 ECT: side-by-side numbers

82 ECT is usually a double wall grade and 90 ECT a triple wall grade, so the comparison here pairs BC double wall with AAC triple wall. Together the higher ECT and thicker board give about 51% more estimated compression strength.

Estimated compression at 10 sizes

Inside, in82 ECT BC90 ECT AACDifference
8 × 6 × 41,3512,038+687 lbf
10 × 8 × 61,5322,310+779 lbf
12 × 12 × 121,7692,668+899 lbf
14 × 10 × 81,7692,668+899 lbf
16 × 12 × 101,9102,882+971 lbf
18 × 12 × 121,9772,983+1,005 lbf
18 × 18 × 182,1663,268+1,101 lbf
20 × 16 × 142,1663,268+1,101 lbf
24 × 18 × 182,3403,529+1,190 lbf
24 × 24 × 242,5013,773+1,272 lbf

Boxes high at 30 lb per box

Inside, in82 ECT90 ECT
10 × 8 × 63147
16 × 12 × 103958
24 × 18 × 184771

Column stacked for 30 days with Packgent's default 40% storage loss (an assumption): ⌊BCT × 0.6 ÷ 30⌋ + 1.

Choosing between them

Pick the lower grade when the stack is short, the load light or the box is used once. Move up when boxes sit in storage for weeks, see humid warehouses, are interlocked or overhang the pallet, because each of those cuts usable strength. The stacking calculator shows which grade your conditions need.

More comparisons

Sources