Paper sizes explained

Though most of us come across hundreds of pieces of A4 paper in the office everyday, and a few of us will even know the difference between A5 and A3, the majority of people don’t really understand what different paper sizes mean and how this can affect their printed projects.

To help you get a better understanding of the world of print, and to ensure you get the best results from your printed pieces, here’s a quick run-down of paper sizes and what they mean for you and your design team.

For a complete list of dimensions see Paper sizes.

A sizes

Thanks to the ubiquitous nature of the A4 page, A sizes are probably the best known of all the paper dimensions.

The largest is A0 which has an area of one square metre. An A0 page folded in half is the size of an A1 piece of paper and A2 has the same dimensions as a folded A1 page. This continues down to A8 which is just half the size of A7 at 52mm x 72mm.

B sizes

The B series of paper sizes follows the same pattern as the A series, with B0 the biggest and B8 the smallest. However, B page sizes fall between A sizes, giving consumers more choice when it comes to picking the right format for their printed product.

The most commonly used B size is B5 which is a popular choice for books and brochures.

C sizes

Unlike A and B sizes which are used for posters, letters, flyers and books, C sizes are generally reserved for envelopes. An unfolded A4 piece of paper will fit perfectly into a C4 envelope, an A5 sheet will go into a C5 envelope and so on.

Folded in half, an A4 sheet will fit snuggly into a C5 envelope, and if its folded twice it will fit perfectly into a C6 sized envelope.

Untrimmed paper

When printing posters, flyers and other products, professional printers often use paper that’s larger than the standard paper size to allow for bleed and trim. These are known as SRA and RA paper sizes and are slightly larger than the corresponding A sizes.

Understanding the difference between standard paper sizes will help you to find the perfect format for your next print project. If you’re still unsure which paper size is right for you, your printer will be able to talk you through the different options available so why not get in touch to find out more.