Box size finder
Packaging tools
Enter your item's dimensions and how much protection it needs. This tool adds padding on every side, then rounds each dimension up to a planning increment. Check the resulting dimensions against an actual product before ordering. Flat, low-profile items get a mailer browsing link.
Planning dimensions
Match your measurements to a product
Use the calculated dimensions as a starting point. Compare all three required inside dimensions with the selected product, including room for your cushioning. The calculator does not check whether a matching size is stocked.
- Browse corrugated shipping boxes by size.
- Browse mailer boxes for lower-profile items.
- For a 10 × 6 × 6-inch inside size, SKU 1066 is a kraft ECT-32 single-wall shipping box, sold in bundles of 25. An order for 100 boxes requires 4 bundles. Choose it only if your item and cushioning fit.
Compare pack counts and delivered cost before ordering. Check the selected product for its current price and delivery estimate; checkout confirms the final total.
How to size a box
Start from the item, not the box. Measure length, width, and height, then decide how much cushioning the contents need — roughly a quarter inch for a snug non-fragile fit, about an inch for typical goods, two inches or more for fragile items. Add that padding to each pair of faces to get the interior you need, then compare the required inside dimensions with an actual product. A box only slightly larger than the item keeps void fill low and helps you stay under the next dimensional-weight threshold.
Common questions
How much space should I leave around my item?
A common rule is roughly 1 inch of cushioning on every side for typical goods and 2 inches or more for fragile items. Tightly fitted, non-fragile products can use about a quarter inch. This tool applies your chosen padding to all four sides and to the top and bottom, since a flat item often needs less lid clearance than side padding.
Why does the interior size add padding on both sides?
Padding sits on each face of the item, so each dimension grows by twice the padding on that pair of faces. A 6-inch-wide item with 1 inch on each side needs an 8-inch-wide interior. Length and width use the side padding; height uses the top-and-bottom padding.
Why round the planning dimensions?
The increments make it easier to compare approximate sizes. They are not a catalog lookup: a combination of three rounded dimensions may not be stocked. Check the inside dimensions of an actual product and allow room for cushioning.
How does box size affect shipping cost?
Carriers bill the greater of actual and dimensional weight, and dimensional weight rises with volume. A box only slightly larger than needed keeps you under the next billable pound, so right-sizing the carton reduces what you pay to ship.
When should I use a mailer box instead?
For flat, lightweight, or lower-profile items, a mailer box can protect the product with less volume and less void fill than a standard cube-shaped box. When your padded item comes out flat, this tool routes you to the mailer option first.