Outside dimensions

What it means in packaging

They matter for shipping cartons, shelving and storage. The relationship to inside dimensions depends on the structure: doubled walls, lids and overlapping panels add different amounts of material. A single thickness formula is not valid for every box.

A practical example

A rollover mailer wall has several board layers, so its external width cannot be inferred by adding just one caliper on each side.

What to check

Measure the closed sample at its widest points, and use the carrier or retailer’s required measurement method.

Use it in your project

• Inside, outside and manufacturing dimensions
• Inside versus outside box sizes

Related terms

Inside dimensions

Inside dimensions describe the space within an assembled package, rather than its external footprint.

Caliper

Caliper is the measured thickness of a sheet material, commonly expressed in millimetres or micrometres.

Mailer box

A mailer box is a packaging format commonly assembled from one blank with a hinged lid and interlocking walls or tabs.