48 ECT EB double wall: box compression and stacking table

48 ECT EB double wall pairs a 48 lb/in edge crush with a nominal 0.188 in caliper. As an empty 12 × 12 × 12 in box, the simplified McKee formula puts it near 845 lbf of top-to-bottom compression before any allowance for storage or humidity.

Compression, derated for storage time

BCT after storage losses, lbf, 48 ECT EB double wall
Inside size, in	0 days	10 days	30 days	90 days	180 days
8 × 6 × 4	646	407	387	355	323
10 × 8 × 6	732	461	439	403	366
12 × 12 × 12	845	533	507	465	423
14 × 10 × 8	845	533	507	465	423
16 × 12 × 10	913	575	548	502	457
18 × 12 × 12	945	595	567	520	473
18 × 18 × 18	1,035	652	621	569	518
20 × 16 × 14	1,035	652	621	569	518
24 × 18 × 18	1,118	704	671	615	559
24 × 24 × 24	1,195	753	717	657	598

0 days is the McKee estimate itself. Storage losses are Packgent's default assumptions (10 days 37%, 30 days 40%, 90 days 45%, 180 days 50%), not sourced values; edit them in the stacking calculator.

How many high can it stack?

Boxes high, including the bottom one, column stacked for 30 days, before humidity, interlock or overhang losses.

12 × 10 × 8 in, BCT ≈ 809 lbf
Gross weight per box	10 lb	20 lb	30 lb	40 lb	60 lb
Boxes high	49	25	17	13	9

16 × 12 × 10 in, BCT ≈ 913 lbf
Gross weight per box	10 lb	20 lb	30 lb	40 lb	60 lb
Boxes high	55	28	19	14	10

20 × 16 × 12 in, BCT ≈ 1,035 lbf
Gross weight per box	10 lb	20 lb	30 lb	40 lb	60 lb
Boxes high	63	32	21	16	11

Boxes high = ⌊BCT × (1 − 0.4) ÷ gross weight⌋ + 1. A real stack needs further allowance for humidity, pattern and handling.

Neighbouring grades

Grade	ECT change	BCT change, same flute and size
42 ECT	-6 lb/in	-12%
51 ECT	+3 lb/in	+6%

In McKee, BCT scales directly with ECT, so the percentage change in strength equals the change in ECT.

Freight rule limits

NMFC Item 222 ties each grade to a maximum gross weight and size for LTL shipping. Packgent has not published those limits yet because they could not be checked against the current tariff. See the Item 222 page for status.

Sources

TAPPI T 811: Edgewise compressive strength of corrugated fibreboard (short column test)
McKee, R.C., Gander, J.W. & Wachuta, J.R. (1963). "Compression strength formula for corrugated boxes." Paperboard Packaging 48(8): 149–159
Flute calipers: Foster (1997), Wiley Encyclopedia of Packaging Technology

Last reviewed 2026-10-27. See all sources and how Packgent computes.