44 ECT vs 55 ECT: side-by-side numbers

55 ECT board crushes at 55 lb per inch of edge against 44 for 44 ECT, so in C flute a 55 ECT box is estimated 25% stronger in compression at any size. Whether that is worth it depends on load, stack height and storage time.

Estimated compression at 10 sizes

Inside, in44 ECT C55 ECT CDifference
8 × 6 × 4540675+135 lbf
10 × 8 × 6613766+153 lbf
12 × 12 × 12707884+177 lbf
14 × 10 × 8707884+177 lbf
16 × 12 × 10764955+191 lbf
18 × 12 × 12791989+198 lbf
18 × 18 × 188661,083+217 lbf
20 × 16 × 148661,083+217 lbf
24 × 18 × 189361,170+234 lbf
24 × 24 × 241,0001,250+250 lbf

Boxes high at 30 lb per box

Inside, in44 ECT55 ECT
10 × 8 × 61316
16 × 12 × 101620
24 × 18 × 181924

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