The number that surprises people sizing a necklace box is that the chain length is almost irrelevant. A chain is not packed straight. It is coiled, folded in half, or draped over a card, and each of those presentations needs a different footprint. Work out how the piece is presented first, then measure that.
Chain lengths and what they mean for the footprint
The jewellery trade uses a published set of chain lengths, and they are a useful checklist rather than a box size. If you coil a chain into a single loop on the pad, the loop diameter is roughly the chain length divided by pi. Fold it in half first and you halve that. The table is the arithmetic.
| Chain length | Single loop diameter | Folded once, then looped |
|---|---|---|
| 16 in (choker) | About 5.1 in | About 2.5 in |
| 18 in (princess) | About 5.7 in | About 2.9 in |
| 20 in | About 6.4 in | About 3.2 in |
| 24 in (matinee) | About 7.6 in | About 3.8 in |
| 30 in (opera) | About 9.5 in | About 4.8 in |
These are industry-typical chain lengths and a geometry calculation, not an iBox size chart. Real chains sit looser than the maths suggests, so treat the figure as the floor and add clearance.
The pad decides the depth
Most necklace boxes hold the piece on a foam pad wrapped in velvet or paper, sometimes with a slot for the chain. The pad is a real component with a real thickness, and it sits inside the internal depth you quote. Measure in this order: pad thickness, then the pendant lying or standing on the pad at its thickest point, then about 1/8 in so the lid does not press on the stone. A box that closes onto the pendant will mark it.
If the necklace hangs on an insert card rather than lying flat, the depth question changes completely, because the card holds the pendant off the base and the box has to be deep enough for the card to stand without bowing.
Internal, external, and why rigid boxes widen
Ask for internal dimensions and say so on the spec. This matters more on jewellery than almost anywhere else, because rigid boxes are built from chipboard wrapped in paper, and the wrap is on both faces. A rigid wall can be several millimetres thick, so a box with a 3 x 3 in cavity can measure noticeably more on the outside. A folding carton in the same cavity size is barely thicker than the board. Confirm which number your quote is answering before you order a display tray or a shipper around it.
Print, finish and the inside surface
The lid interior is visible the moment the box is opened, and it is the panel most often left blank by accident. Decide early whether it is printed, foiled, debossed or plain. Foil and embossing behave differently on rigid wrap than on carton board, and the technique comparison on embossing vs debossing is worth reading before you commit artwork.
What it costs and how long it takes
Necklace boxes start at 100 units. Pricing runs from about $0.48 per unit at bulk volumes, confirmed on your written quote, and the cutting die, the plates, design support, US shipping and a digital proof are included. Turnaround is stated per product across three lanes, rush (expedited production plus air freight), standard (air) and cost saver (sea), from about 7 business days of production plus 2 to 5 days for delivery. Rigid and specialty imported constructions can run up to about 12 weeks, so raise your date early. Production runs from West Chicago in the US and Guangzhou in China.
Send your longest chain length, how the piece is presented, and the pendant thickness, and we will size the cavity for you. Start at request a quote, or order from the custom necklace boxes page. For the smaller pendant-only format, see how to size a pendant box.
