48 ECT BC double wall: box compression and stacking table

48 ECT BC double wall pairs a 48 lb/in edge crush with a nominal 0.281 in caliper. As an empty 12 × 12 × 12 in box, the simplified McKee formula puts it near 1,035 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 BC double wall
Inside size, in	0 days	10 days	30 days	90 days	180 days
8 × 6 × 4	791	498	474	435	395
10 × 8 × 6	897	565	538	493	448
12 × 12 × 12	1,035	652	621	569	518
14 × 10 × 8	1,035	652	621	569	518
16 × 12 × 10	1,118	705	671	615	559
18 × 12 × 12	1,158	729	695	637	579
18 × 18 × 18	1,268	799	761	697	634
20 × 16 × 14	1,268	799	761	697	634
24 × 18 × 18	1,370	863	822	753	685
24 × 24 × 24	1,464	922	879	805	732

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 ≈ 991 lbf
Gross weight per box	10 lb	20 lb	30 lb	40 lb	60 lb
Boxes high	60	30	20	15	10

16 × 12 × 10 in, BCT ≈ 1,118 lbf
Gross weight per box	10 lb	20 lb	30 lb	40 lb	60 lb
Boxes high	68	34	23	17	12

20 × 16 × 12 in, BCT ≈ 1,268 lbf
Gross weight per box	10 lb	20 lb	30 lb	40 lb	60 lb
Boxes high	77	39	26	20	13

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.