What size mailer box do I need?
Measure your product, add a little room for padding, and pick the closest stock size. Going even half an inch smaller can save $300 on 250 boxes.
By Supply Run · prices checked Nov 2, 2026 · shipping not included
How to measure
- Measure your product (or the largest order you ship) at its widest points: length, width, height.
- Add room for padding. About ¼" on every side for a snug fit, so ½" to each measurement. Add more if you use tissue, crinkle fill or bubble wrap.
- Pick the closest stock size that fits. Stock sizes are almost always cheaper than custom ones.
- Check how the supplier measures. Most quote inside dimensions, which is what your product needs. Packhelp quotes outside dimensions, so its boxes are a little smaller inside.
Mailer box sizes are written length × width × depth. The depth is the height of the box when it's closed.
Common sizes and what fits
Rough examples, plus the cheapest full-color price per box at 250 boxes.
| Size (inches) | Usually fits | From, per box |
|---|---|---|
| 5 × 3 × 1.5 | Jewelry, a bar of soap, small cosmetics, greeting cards | $0.91 |
| 6 × 5 × 2.25 | Soap sets, a skincare duo, small accessories | $1.80 |
| 6 × 4 × 3 | Candle tins, small cosmetics sets, tea or coffee pouches | $2.02 |
| 7 × 5 × 3 | Skincare sets, folded baby clothes, a small candle lying down | $2.50 |
| 8 × 6 × 3 | A paperback, a folded T-shirt, small gift sets | $2.76 |
| 12 × 9 × 2 | Flat items: folded shirts, prints, notebooks | $3.15 |
| 9.5 × 7.75 × 4 | A candle jar, a mug, a folded sweatshirt | $3.37 |
| 10 × 8 × 4 | A hoodie, a hardcover book, two or three small products | $4.57 |
| 12 × 10 × 4 | Gift sets, several items together, a folded jacket | $4.50 |
| 14 × 10 × 4 | Bundles, folded jeans, larger apparel orders | $5.65 |
Always test with your actual product. Product sizes vary a lot, even within a category.
Smaller is cheaper, twice
A box that's only slightly smaller can cost noticeably less. Going from 10 × 8 × 4 to 9.5 × 7.75 × 4 drops the cheapest full-color price from $4.57 to $3.37 per box, about $300 less on 250 boxes.
Smaller boxes can also cost less to ship, since carriers charge by size as well as weight. And a snug box needs less filler, which looks better when it's opened.
Don't see your size?
Several suppliers price custom sizes online instantly. In our comparison, choose "Custom size", enter your measurements, and we'll show the closest stock size, plus the suppliers that will make your exact size.
See your size in 3D
The comparison shows each size as a 3D box with its measurements, next to every supplier's price.
Open the box sizer