Mailer boxes, also called flap boxes, are die-cut corrugated boxes that fold into shape and lock without tape. They are the go-to box for D2C brands shipping cosmetics, jewellery, apparel and gifts. This guide explains how mailer box sizes are measured and lists every size we stock. It also helps you choose between a mailer box and a regular carton.
How mailer box sizes are measured
Our mailer box sizes are written as length × width × height in inches, inner size. That means the space your product actually gets. To choose a size:
- Measure your product (or its retail box) at its longest, widest and tallest points.
- Add space for any cushioning you use, such as shredded paper, honeycomb wrap or bubble wrap. About 0.25 to 0.5 inch on each side is usual.
- Pick the smallest box that is equal to or bigger than those numbers. A snug fit stops the product moving and keeps courier volumetric weight low.
Prefer not to calculate? Our Box Size Finder does it for you. Enter your product’s L × W × H and it shows the mailer and carton boxes that fit.
Brown mailer box sizes
Natural kraft, 3 ply corrugated, die-cut and self-locking. All sizes below are inner sizes in inches.
We stock 20 sizes: 4.5×3×1, 4×4×1.5, 4×4×2, 4×4×3, 5×3×2, 5×5×2, 6×3×2, 6×4×2, 6×4×3, 6×5×2, 7×3×2, 7×5×2, 7×7×2, 8×4×2, 8×5×2, 9×5×2, 9×6×3, 10×5×2, 12×5×2 and 12×10×3 inch.
Shop: Brown mailer boxes
White mailer box sizes
White outer surface for a cleaner, premium unboxing look, 3 ply corrugated. All sizes below are inner sizes in inches.
We stock 21 sizes: 4.5×3×1, 4×4×1.5, 4×4×2, 4×4×3, 5×3×2, 5×5×2, 5×5×3, 6×3×2, 6×4×2, 6×5×2, 7×3×2, 7×5×2, 7×7×2, 8×4×2, 8×5×2, 9×5×3, 9×6×3, 10×5×2, 10×5×3, 12×5×2 and 12×10×3 inch.
Shop: White mailer boxes
Which size for which product?
| Product type | Sizes to start with (inches) |
|---|---|
| Rings, earrings, small jewellery | 4.5×3×1, 4×4×1.5 |
| Lipsticks, small cosmetics, candles | 4×4×2, 4×4×3, 5×5×2 |
| Watches, perfumes, skincare sets | 6×4×2, 6×4×3, 7×5×2 |
| Folded T-shirts, accessories, gift sets | 8×5×2, 9×6×3, 10×5×3 |
| Larger hampers, shirts, combo orders | 12×10×3 |
These are starting points only. Always measure your own product, because packaging differs from brand to brand.
Mailer box or carton box?
- Mailer (flap) box: folds and locks without tape, looks neat when opened, and suits small and medium D2C products.
- 3 ply carton box: a regular single-wall shipping carton, sealed with tape, good value for everyday parcels. See 3 ply corrugated boxes.
- 5 ply carton box: double-wall and much stronger, for heavy or fragile items, bulk shipments and house shifting. See 5 ply corrugated boxes.
Frequently asked questions
Are the sizes inner or outer?
Mailer box sizes listed here are inner sizes, which is the usable space inside the box.
Do mailer boxes need tape?
No. They are die-cut and self-locking, so the flap tucks in and holds. Some sellers add a strip of tape or a seal sticker for extra security.
How are boxes delivered?
Boxes are supplied flat-packed in packs and fold into shape before use. Delivery is free across India and every order comes with a GST invoice.
Can I order in bulk?
Yes. Packs go up to 500 boxes online, and for regular larger orders you can request a bulk quote.
