Packaging Guides
Poly Mailer Sizes: Complete Guide for E-Commerce Shipping (2026)
Cubit Packaging Team
May 12, 2026
4 min read
Poly Mailer Sizes: Which Size Is Right for Your Products?
Choosing the correct poly mailer size ensures your product fits snugly, arrives protected, and minimizes shipping costs. Here's every standard size with product fit recommendations.
Quick answer: The 10×13" poly mailer is the most popular size — it fits most t-shirts, blouses, lightweight pants, and small accessories with appropriate clearance.
Standard Poly Mailer Sizes
| Size (W×L) | Usable Space | Weight Range | Best For |
|---|---|---|---|
| 6×9" | 5.5×8.5" | Under 4 oz | Jewelry, phone cases, small accessories |
| 7.5×10.5" | 7×10" | 4–8 oz | T-shirts (folded), underwear, socks |
| 10×13" | 9.5×12.5" | 8 oz–1 lb | Most clothing, small accessories |
| 12×15.5" | 11.5×15" | 1–2 lb | Jeans, hoodies, sweaters |
| 14.5×19" | 14×18.5" | 2–3 lb | Jackets, dresses, multi-item orders |
| 19×24" | 18.5×23.5" | 3–5 lb | Bedding, pillows, bulky items |
| 24×36" | 23.5×35.5" | 5+ lb | Comforters, large textiles |
Size by Product Type
Apparel
| Product | Recommended Size | Notes |
|---|---|---|
| Socks, underwear (1 pair) | 6×9" | Smallest size, lowest shipping cost |
| T-shirt (1) | 7.5×10.5" or 10×13" | Fold in thirds, 10×13 allows tissue wrap |
| Polo shirt, dress shirt | 10×13" | Standard fold with collar card |
| Jeans, pants | 12×15.5" | Roll for best fit |
| Hoodie, sweatshirt | 12×15.5" or 14.5×19" | Depends on fabric weight |
| Winter jacket, coat | 14.5×19" | Compress and fold tightly |
| 2-3 item order | 14.5×19" | Most multi-item apparel orders |
| 4+ item order | 19×24" | Largest standard size |
Accessories & Small Items
| Product | Recommended Size | Notes |
|---|---|---|
| Phone case, jewelry | 6×9" | Add bubble wrap or card insert |
| Books, notebooks | 10×13" | Consider bubble mailer for protection |
| Cosmetics, small beauty | 7.5×10.5" | Use bubble mailer for glass items |
| Shoes (1 pair in box) | 14.5×19" | Most shoe boxes fit this size |
How to Choose the Right Size
- Measure your product — folded/packaged dimensions (L×W×H)
- Add 1–2 inches of clearance on width and length
- Account for inserts — tissue paper, thank-you cards, stickers add bulk
- Consider the seal flap — the usable space is ~0.5" less than stated size
- Test with a sample — always order samples before committing to a size
Sizing Rule of Thumb
Product width + 2" = mailer width. Product length + 2" = mailer length. This gives 1" clearance on each side for comfortable insertion and closure.
Common Sizing Mistakes
❌ Too Small
- Product is forced in, causing the mailer to stretch and potentially tear
- Self-seal flap doesn't adhere properly
- Poor unboxing experience for the customer
❌ Too Large
- Product slides around, creating a sloppy presentation
- Excess material adds unnecessary weight and cost
- More likely to get caught in sorting machines
✅ Just Right
- Product slides in easily with 1–2" clearance
- Seal flap closes flat with full adhesive contact
- Professional appearance when received
Custom Sizes
If standard sizes don't fit your product, Cubit offers custom dimensions:
- Minimum custom size: 4×6"
- Maximum custom size: 30×40"
- Custom tooling: $200–$500 (one-time)
- MOQ for custom sizes: 1,000 units
- Lead time: 10–14 days (vs 7–10 for standard)
Not sure which size fits your product? Request free samples in multiple sizes or ask our AI consultant. Browse our poly mailer collection.