Jiffy Bag Sizes Guide: Size 00 to 8 in mm & Inches
Key Takeaway
Every Jiffy bag size from 00 to 8 in mm and inches, what fits in each, and which size to choose for A4 documents, books and clothing.
Jiffy bags are sold by size number, from size 00 up to size 8. If you already use a size, you can reorder by number. If you are choosing for the first time, this guide shows every size in millimetres and inches, what fits in each one, and how to pick the right bag.
Short answer
For flat A4 documents, use size 4 (225 × 343 mm). For a thicker A4 stack or a book, use size 5 (245 × 381 mm). For A5, use size 1 (165 × 280 mm).
Jiffy bag sizes chart
All sizes are internal dimensions, width × length, for paper-padded Jiffy bags. The size number is the same across suppliers, but bubble-lined mailers can use slightly different measurements for the same number, so always check the millimetres.
| Jiffy size | Internal size | Inches | Typical uses |
|---|---|---|---|
| Size 00 | 105 × 229 mm | 4.1 × 9 in | Keys, small parts, small electronic items |
| Size 0 | 135 × 229 mm | 5.3 × 9 in | Phones, card decks, small cosmetics |
| Size 1 | 165 × 280 mm | 6.5 × 11 in | Paperbacks, A5 documents, DVDs |
| Size 2 | 195 × 280 mm | 7.7 × 11 in | Hardback books, tablets |
| Size 3 | 195 × 343 mm | 7.7 × 13.5 in | Diaries, games, clothing accessories |
| Size 4 | 225 × 343 mm | 8.8 × 13.5 in | A4 documents flat, thin magazines, certificates |
| Size 5 | 245 × 381 mm | 9.6 × 15 in | Thicker A4 stacks, books, small clothing orders |
| Size 6 | 295 × 458 mm | 11.6 × 18 in | Folded clothing, large catalogues |
| Size 7 | 341 × 483 mm | 13.4 × 19 in | A3 documents, larger gifts |
| Size 8 | 442 × 661 mm | 17.4 × 26 in | Bulky and oversized items |
How to choose the right size
- Measure the item, including any box or wrapping.
- Add about 10 mm to the width and length. The padding takes up space inside the bag, and the item must lie flat with room for the flap to close.
- For thick items, add the thickness to both the width and the length, because the bag has to wrap around it.
- If an item is between two sizes, choose the larger one. A bag that is too tight can split at the seams.
A4 documents: size 4 or size 5?
Size 4 (225 × 343 mm) fits a flat A4 sheet (210 × 297 mm) or a thin document wallet. Size 5 (245 × 381 mm) is the better choice for a thick stack of A4 paper or a hardback book, because it leaves room for the depth of the contents.
Posting costs
Postage depends on the size, thickness and weight of the filled parcel, not on the bag number. Check the outside size of the filled bag against the Royal Mail price finder or your courier's limits before you choose a service.
Why choose paper-padded Jiffy bags
Paper-padded Jiffy bags are lined with a thick layer of macerated (shredded) recycled paper. The padding protects against knocks, edges and punctures, so they suit books, tools, metal parts and other heavy or hard-edged items. Both the outer and the padding are paper, so the bag can go in paper recycling.
For lighter items, padded mailing envelopes are thinner and lighter. For soft goods that do not need padding, grey mailing bags are the lowest-cost option.
See every size, pack quantity and trade price on our Jiffy padded bags page.
Ready to order packaging featured in this guide?
Explore full sizing specs, volume discount tiers, and instant pallet pricing in our live catalog matrix.
Related Technical Guides
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How to Ship Clothes: Mailing Bags and Grip Seal Bags
