The same box has two valid measurement sets. Choosing the wrong set can create a fit failure or an inaccurate shipping calculation.

Definitions and operating notes

Internal length
Usable inside length between the carton walls.
Internal width
Usable inside width after accounting for board and construction.
Internal height
Usable depth from the inside bottom to the intended closure plane.
External length
Finished outside length after forming, filling, and closing.
External width
Finished outside width, including any bulge or protruding closure.
External height
Finished outside height at the maximum point.
Use internal for
Product fit, wrap allowance, dividers, inserts, and void volume.
Use external for
DIM weight, length plus girth, storage footprint, and carrier size checks.
Reference note. Confirm current supplier and carrier specifications before using a term or value operationally.

Last reviewed: July 26, 2026