Paper Sizes

Paper Sizes – ISO 216 Standard

The ISO 216 is an international standard for paper sizes used around the world. The standard defines three paper sizes, known as “A”, “B” and “C” Series.

A Series

Use our visual tool below to understand the A Series. The largest A Size available is A0, which when folded in half becomes A1. This pattern is continued through the whole A Series. The smallest A size available is the A8.

B Series

Although it looks almost identical to the A Series, the B Series does differ very slightly. The sizes are based on the geometric mean of two consecutive A Series sheets. As an example, B3 is between A2 and A3 in size.

C Series

Most commonly used for envelopes, the C Series is used to accompany the A and B series papers.