Most pendant boxes are sized wrong for the same reason: the buyer measures the pendant. The pendant is usually the smallest thing in the box. The chain is what decides the footprint, and the pad and the lid decide the depth.
Coil the chain and measure that
Chains are sold at published lengths, so you can work out the coil before you have a sample in hand. A chain laid flat in a single circle has a diameter of roughly its length divided by pi. Fold it in two and the circle halves.
| Chain length | Single loop, approximate diameter | Doubled loop, approximate diameter |
|---|---|---|
| 16 in | About 5.1 in | About 2.5 in |
| 18 in | About 5.7 in | About 2.9 in |
| 20 in | About 6.4 in | About 3.2 in |
| 24 in | About 7.6 in | About 3.8 in |
These are geometry, not a size chart, and a real chain never coils as neatly as the maths. Treat the doubled figure as the working minimum for a box where the chain loops around a pad or a card, and add clearance so the customer can lift the piece out without unpicking it. A rope or curb chain with real bulk needs more room than a fine cable chain of the same length.
Depth, pads and the lift-out moment
Internal depth is three things added together: the pad or insert the pendant rests on, the pendant at its thickest point, and any foam or flock in the lid that holds the piece still. A domed or gemstone pendant can be several times thicker than the chain, so measure it at the stone, not at the bail. If the pad slits hold the chain, check that the pendant sits below the lid line when the box is closed, because a pendant pressing against the lid is what marks the finish.
Think about the opening as well. A tight lift-out insert that a customer has to prise at is a bad first impression on a gift. Leave a finger relief or a ribbon pull if the pad fills the footprint.
Rigid walls add to the outside
A rigid pendant box is chipboard wrapped in printed paper, and chipboard commonly runs about 1.5 to 3 mm depending on the grade. That is small until you multiply it: a wall on each side, a base, a lid, and a lid that laps over the base. The result is an external size that can sit close to half an inch larger than the internal cavity across a small box. If the box has to fit a retail display, a pouch or a shipper, size that fit from the outside number and confirm which number your quote is stating. Folding carton and E flute alternatives sit thinner and cost less, and the trade-off is described on rigid box versus corrugated box.
Ordering
Minimum is 100 boxes, from about $0.48 per unit at bulk volumes, confirmed on your written quote. The die, the plates, design support, US shipping and a digital proof are included, so a cavity cut to your exact chain and pendant is not a premium over a near standard one. Production is quoted per product in three lanes, rush (expedited production plus air freight), standard (air) and cost saver (sea), from about 7 business days, plus 2 to 5 for delivery, and specialty rigid work with wrapped paper and magnets can run up to about 12 weeks. We make in West Chicago and Guangzhou.
Send the chain length, the pendant measured at its thickest point, and whether you want the chain doubled or looped around a card with your quote request. If you are ordering rather than specifying, custom jewelry gift boxes is the place to start the order.
