The honest answer is that nobody can give you a half slotted box size without three pieces of information, and once you have them the size is obvious. This page is the short route: answer three questions, read the decision table, send the numbers.
Question 1: what holds the product in place?
This is what turns a product measurement into a box measurement. If a die cut insert holds it, add the insert wall caliper on each side. If void fill holds it, add the thickness of fill you intend on each side. If nothing holds it, add only a working clearance so the product loads without scraping, and accept that it will move in transit.
Question 2: how heavy is one loaded box?
Weigh it, or estimate the product weight and add the packaging. This number, more than anything about the product itself, drives the board grade. A light product in a big box and a heavy product in a small one need different board even if the dimensions match.
Question 3: how high will they stack?
Boxes stacked three high in a van and boxes stacked to the ceiling of a warehouse rack are different engineering problems. The bottom box carries everything above it, and that load is the reason double wall exists.
Decision table
| Your situation | What to specify |
|---|---|
| Light product, low stack, retail delivery | Single wall, tight internal size, minimal clearance |
| Heavy product, warehouse stacking | Double wall, and confirm the stack height on the quote |
| Fragile product | Insert or fill, then size the box on the product plus that thickness |
| Tray with a separate cap | Size the tray internally, then size the cap on the tray's external dimension |
| Mixed SKUs in one box size | Size on the largest SKU, and price a second die, which is included |
The part people get wrong
Internal versus external. A half slotted box quoted at 12 x 10 x 6 in internal is physically larger on the outside by roughly twice the board caliper per axis, which on C flute is about 3/8 in. If you are matching an existing box, or fitting a carton into a fixed shelf or pallet footprint, say explicitly which measurement you are giving. The full method, including the flap geometry and the flute conversion table, is on our half slotted box size guide.
What to send us
Three product dimensions, what holds the product, the loaded weight, the stack height, the quantity, and whether you need a cap. That is enough to quote a size, a board and a price. Minimum order is 100 boxes, from about $0.48 per unit at bulk volumes, confirmed on your written quote, with the die, the plates, design support, US shipping and a digital proof included. Turnaround is quoted per product in three lanes: rush (expedited production plus air freight), standard (air) and cost saver (sea), from about 7 business days in production plus 2 to 5 days for delivery. To see the stock formats first, visit corrugated boxes.
If you have the three product dimensions and a quantity, that is enough to start. Request a quote and we will come back with a size and a board grade.
