Bubble mailer sizes follow a standard number scale from #000, the smallest, to #7, the largest, plus a #CD square format. The number refers to a nominal envelope size — the usable interior is slightly smaller once the seal and bubble loft are accounted for. Sizing correctly matters twice: an oversized mailer wastes money and invites the product to move in transit; an undersized one stresses the seams and the seal.
The standard size chart
Nominal exterior dimensions for the standard run we manufacture:
- #000 — 4 × 7 in: jewelry, SD cards, small electronics accessories
- #00 — 5 × 9 in: phone cases, cosmetics, small parts
- #0 — 6 × 9 in: photos, CDs in cases, passports and documents
- #CD — 7.25 × 7 in: discs and square flat goods
- #1 — 7.25 × 11 in: phone boxes, small books
- #2 — 8.5 × 11 in: letter-size documents, tablets in cases
- #3 — 8.5 × 13 in: legal documents, small apparel
- #4 — 9.5 × 13 in: books, small boxed goods
- #5 — 10.5 × 15 in: clothing, larger books
- #6 — 12.5 × 18 in: framed photos, boxed kits
- #7 — 14.25 × 19 in: the largest standard — multi-item orders, large flats
How to choose in three steps
First, measure the item's length, width and thickness, and add roughly an inch to length and width for insertion and seal. Second, choose the facing: poly (white film) resists moisture and weight for its cost; kraft and white-kraft give a paper feel and print surface; color bubble differentiates the unboxing. Third, sanity-check against your carrier's dimensional rules — a mailer that keeps the package under the carrier's dimensional-weight thresholds ships at the lightest possible billed weight.
If your product is soft and non-fragile — apparel, textiles — a flat poly mailer without bubble is usually cheaper and lighter. If it can dent, scratch or crack, the bubble lining earns its keep.
Quick answers
What is the most common bubble mailer size?
Sizes #0 (6 × 9 in) and #2 (8.5 × 11 in) are the workhorses of e-commerce — #0 for small accessories, #2 for letter-size and tablet-class items.
Are bubble mailer dimensions interior or exterior?
Nominal sizes are exterior. Usable interior width is typically about half an inch less, and usable length shortens by the closure flap — size up if the fit is tight.
Poly, kraft or white kraft — which facing should I use?
Poly resists moisture and tears at the lowest weight; kraft offers a natural paper look; white kraft prints cleanly for branding. Protection comes from the bubble lining in all three.
