Swimwear has no fixed dimensions. A bikini top folds to almost nothing, a one piece with moulded cups does not fold flat at all, and a set with a cover up is three items in one pack. That is why sizing a swimwear box begins with a decision rather than a measurement: choose how the garment is folded, and the box follows from there.
Choose the fold, then measure it
| Fold pattern | What it produces | Suits |
|---|---|---|
| Thirds, lengthwise | A long narrow stack | Sleeve boxes and slim mailers |
| Quarters | A compact squarish stack, more depth | Rigid gift boxes and cube mailers |
| Rolled | A cylinder, low crease risk | Tube packaging and subscription boxes |
| Flat with a card insert | Minimum depth, maximum footprint | Flat mailers where postage is banded by thickness |
Fold a real garment in the pattern you have chosen. Do it with the largest size in your range, because an XL one piece with moulded cups is a very different stack from a small bikini brief, and a box cut for the small will not take the XL.
Measure with the right pressure
Press the folded stack with light, even hand pressure, the way a packer would, and measure it there. Do not measure it flattened under a weight, because the garment relaxes in the box and pushes the lid open. Do not measure it loose either, because you will end up with a box full of air. Take length, width and height of that stack and add roughly 1/8 in in each axis.
Add everything that goes in with it
Swimwear rarely ships alone. A poly bag or a compostable film bag adds thickness around the whole stack. A hygiene liner adds a sheet. A swing tag with a plastic loop is small but does not compress. Tissue adds real depth if you use several sheets. Care cards, a size sticker and a returns slip all stack up. Assemble the complete pack, then measure it, rather than measuring the garment and adding an allowance from memory.
Choosing the format
Three routes, and the sizing consequence of each:
- Mailer box. Ships direct, takes a courier, and the depth is fixed so the fold has to match it. Print inside for the unboxing.
- Sleeve or belly band. Minimum material, the garment is visible, and the sizing is forgiving because a sleeve tolerates a range of stack thicknesses. See the apparel sleeve boxes page for that format.
- Rigid gift box. Best hand feel, highest cost, and the least tolerant of a stack that is slightly too thick, because a rigid lid does not flex.
Moisture, print and the thing that catches people out
Swimwear is sometimes returned or handled damp, and damp board loses stiffness quickly. If your pack doubles as the returns box, specify a coating or a board that tolerates handling, and say so on the spec rather than assuming it.
Lead time and minimum
Apparel packaging starts at 100 units, from about $0.48 per unit at bulk volumes, confirmed on your written quote. The cutting die, the printing plates, design support, US shipping and a digital proof are included, so a box cut to your actual folded stack costs no more to tool than a near standard size. 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. Rush carries a premium of roughly 7 to 25% depending on the job.
Fold your largest size, measure the stack with the bag and tags on, and send us those three numbers. Start at request a quote, or order from the custom swimwear boxes page.
