DKCD
All tools / Box fit and clearance

Box fit and clearance.

Start from the product, add clearance for the insert or protective material, and get the internal and external carton dimensions you need to spec. Works for corrugate, folding carton, foam, and bag-in-box setups.

Inputs.

Product dimensions plus clearance per side. Clearance presets cover common protective materials.

Results.

Internal dimensions are what you spec to the box supplier. External dimensions are what hits the shipper, shelf, or pallet.

Internal dimensions (L x W x H)8.125 x 5.125 x 3.125 in
External dimensions (L x W x H)8.375 x 5.375 x 3.375 in
Total clearance, length axis0.125 in
Total clearance, width axis0.125 in
Total clearance, height axis0.125 in
Internal volume130.1 cu in
Fit checkProduct fits with clearance
Rules of thumb: clearance applies per side, so the internal dimension grows by twice the clearance on each axis. Height in a top-load carton usually only needs clearance above the product, so tighten the height clearance if the product sits on the carton floor. For club store trays and PDQ displays, confirm clearances against the retailer's fill and squareness specs before tooling.

Disclaimer: These tools were built at my desk to keep the answers I need in one place. I’m sharing them in the hope that they make your design process a little easier too. The math is checked against published standards and real-world experience, but specs change and materials vary. If you spot anything that seems off, please email me at donna@donnakadell.design and I’ll take a look.

Enjoy.