Size Guides

Please see below for our size guides, designed to help you choose the perfect packaging, no matter watcha packin’!

Printed Bubble Mailers

Our handy Bubble Mailer size guide below will help you work out which standard mailer you will need, giving you an idea on bubble mailer size for the future.

A standard C5 Bubble Mailer measures 180mm x 250mm. This is designed to fit A4 paper folded in half, or A5 paper unfolded. Standard A5 paper size is 148mm x 210mm.

A standard C4 Bubble Mailer measures 240mm x 340mm. This is designed to fit unfolded A4 paper. Standard A4 paper size is 210mm x 297mm.

A standard C3 Bubble Mailer measures 320mm x 450mm. This is designed to fit unfolded A3 paper (which is double the size of A4 paper). The standard A3 paper size is 297mm x 420mm.

Packing Boxes

The first step to finding the right box is measuring your items. You will need to select a box which is slightly larger than all 3 dimensions to allow you to add protection by wrapping your products in protective tissue or bubble wrap, to stop items moving around during transit.

Packing Boxes Dimensions

Our box measurements are internal and are given in the following order: Length x Width x Height. This is a standard way boxes are measured within the industry.


Length: Longest side of the box opening.

Width: Shortest side of the box opening.

Height: Box depth from the opening to the bottom.

Standard Paper Size Guide

The dimensions of the A series paper sizes, as defined by the ISO 216 standard, are given in the table below. The A Series paper size chart, gives a visual representation of how the sizes relate to each other – for example A5 is half of A4 size paper and A2 is half of A1 size paper.