Double wall does not name a size. It names a board construction: three liners with two fluted mediums between them. So the honest answer to "what are double wall box dimensions" is that you pick the internal dimensions your product needs, and the double wall build then tells you how much thicker the finished box is than that internal cavity. The figures below are published industry-typical board calipers, not an iBox stock list.
What the board build fixes
Each flute profile has a well known approximate caliper. Glue two profiles together and the finished board is close to the sum of the two, plus a small amount for the liners and adhesive. That is why a double wall carton eats more internal volume than a single wall carton of the same outside size.
| Double wall combination | Approximate caliper (industry-typical) | What it is usually chosen for |
|---|---|---|
| EB | about 3/16 in (4.8 mm) | Retail-facing shippers where the E liner keeps print crisp |
| BC | about 9/32 in (7 mm) | The common heavy-duty shipper, good stacking and puncture resistance |
| AC | about 13/32 in (10 mm) | Bulky or high-mass loads where cushioning matters more than cube |
Internal versus external, the gap that causes reprints
Most reprints we see start here. A buyer measures the product, writes down a number, and never says whether that number is the cavity or the outside of the carton. On BC board at roughly 9/32 in, a box with a 12 x 12 x 12 in internal cavity finishes near 12 9/16 in on length and width, because you add one board caliper at each wall. Over a pallet layer that difference decides whether you fit four across or three.
Write your spec as internal length x width x depth and say the word "internal". If you are matching an existing box you bought elsewhere, measure the cavity with the flaps open rather than the outside with a tape.
Setting your own internal size
- Measure the product at its widest point, not its nominal point. Handles, lids and seams all count.
- Add clearance for whatever surrounds it. A fitted insert needs its own wall thickness; loose void fill needs more.
- Order the three figures longest, second longest, then height, so length x width x depth is unambiguous.
- Check the footprint against a standard 48 x 40 in pallet before you commit. A 12 x 10 in footprint gives 16 cartons per layer with no overhang, which is the kind of fit that quietly lowers your freight cost.
Ordering, minimums and lead time
Minimum order is 100 boxes. Price starts from about $0.48 per unit at bulk volumes and is confirmed on your written quote, because board grade, print coverage and finishing all move it. The cutting die, the plates, design support, US shipping and a digital proof before anything prints are included, which is the practical reason not to force your product into a near-standard size: a custom internal dimension does not carry a tooling penalty here.
Production runs out of two plants, West Chicago in the US and Guangzhou in China, in three lanes. Rush is expedited production plus air freight and carries a premium of about 7 to 25% depending on the job. Standard moves by air. Cost saver moves by sea. The floor is from about 7 business days, plus 2 to 5 for delivery, and specialty imported items can run up to about 12 weeks.
If you want to compare a double wall build against a heavier single wall, read what C flute actually does, or look at the stock styles on the corrugated boxes and double wall tuck top pages. When you have an internal dimension and a rough annual volume, send both through the quote form and you will get board options priced side by side rather than a single take-it-or-leave-it number.
