Mailer box size chart
Mailer box sizes (4x4x4 through 16x12x6) with product mapping
Mailer boxes (rigid corrugated mailers, also called e-commerce mailers, deluxe literature mailers, or roll-end tuck-top boxes) are sized by length x width x depth in inches and ship flat. Pick the smallest box that fits the product plus minimal void fill - oversized boxes inflate dimensional weight and need more dunnage to keep the product from rattling.
Use the chart below to map common product types (subscription box, jewelry, candles, mid-size apparel) to a recommended mailer box size.
Mailer box size chart (with what fits)
| Box size L x W x D (in) | Best for | Common items | Shop |
|---|---|---|---|
| 4 x 4 x 4 | Tiny gift box / small jewelry mailer | Single ring or earring set, small candle votive, sample-size cosmetics | 4x4x4 -> |
| 6 x 6 x 4 | Small subscription cube / jewelry set | Necklace + box, small skincare set, single 8 oz candle, mug | 6x6x4 -> |
| 8 x 6 x 2 | Slim subscription / accessory mailer | Watches, sunglasses, wallets, slim books, planners | 8x6x2 -> |
| 9 x 6 x 3 | Standard small subscription box | Snack box, mini cosmetics set, paired candle + soap, novella + booklet | 9x6x3 -> |
| 10 x 8 x 4 | Mid-size subscription / multi-candle | 2-3 candle set, beauty box, small electronics with insert tray, kitchen gadget | 10x8x4 -> |
| 12 x 9 x 3 | Folded apparel / book mailer | 1-2 folded tees, magazines, hardcover book, framed 8x10 print | 12x9x3 -> |
| 12 x 9 x 4 | Mid-size apparel / pajamas / sneakers | Folded hoodie, pajama set, low-profile sneakers, kids gift set | 12x9x4 -> |
| 12 x 12 x 6 | Square subscription / multi-product box | 4-6 candle set, snack subscription cube, ceramics, pet starter kit | 12x12x6 -> |
| 14 x 10 x 3 | Apparel mailer / slim multi-piece | 2-3 folded tees, folded button-down, swimsuits set, light scarves | 14x10x3 -> |
| 16 x 12 x 6 | Large subscription / bulky apparel | Bulky hoodies, puffer jackets, multi-pair shoe drop, large gift sets | 16x12x6 -> |
Product-type quick map. Single jewelry: 4x4x4. Single 8 oz candle: 6x6x4. Subscription cube (snacks/beauty): 9x6x3 to 10x8x4. Folded apparel: 12x9x3 (1-2 pieces) or 14x10x3 (3+ pieces). Bulky hoodies / puffers: 16x12x6. Run the actual product through the box size calculator for exact dimensional weight.
Mailer box FAQ
What is the difference between a mailer box and a regular shipping box?
Mailer boxes are roll-end tuck-top corrugated boxes that ship flat and assemble without tape - the front panel folds down and the side wings tuck into the base. Regular shipping boxes (RSC, regular slotted containers) need tape on the top and bottom seams. Mailers are more brand-friendly (printable interior, no tape) and faster to assemble for ecommerce, but RSCs are cheaper for plain bulk shipping.
Do I need a 32 ECT or 200# test mailer box?
For most ecommerce mailers under 30 lb, 32 ECT B-flute is the default - lighter, lower DIM weight, and certified for parcel shipping. Use 44 ECT or 275# test only if the contents are heavy, fragile, or stacked on a pallet. See 32 ECT vs 200# test for the full breakdown.
How much void fill do I need inside a mailer box?
Aim for under 0.5 inch of free space on every axis. Use a kraft crinkle layer or sized insert tray for branded boxes, or air pillows / paper for utility boxes. More than 0.5 inch and the product shifts in transit, which causes label scuffing and box damage; less than 0.25 inch and the box is too tight to close cleanly.