What is A4 Size?

One of the biggest questions we are asked is an A4 Size? So what size is A4 paper? A4 size is 210mm x 297mm and the most common paper size in the UK. The UK’s paper sizes are different from US paper sizes, but there’s a whole array of sizes to choose from. Different formats work best for various printing needs. Below we detail all the UK paper sizes including A4 paper size, A3 paper size, A2 paper size, A1 paper size and also A0 paper size.

A4 Paper Size

What size is A4 paper? And A3 and A5 and A0 for that matter! Well the most common paper sizes used in the UK for print and business stationery are all named using the letter A. This is also known as Standard International Paper Sizes. The range begins with  A10 (37mm x 26mm) all the way up to the massive A0 (1189mm x 841mm) size..

With A sized paper, however many times you double the short edge or half the long edge, it will always have the same width to height ratio. For example, the dimensions of A4 paper are 210x297mm, and half of A4 equals A5, and double A4 equals A3.

If you start from A0, all subsequent “A” paper sizes are determined by halving the paper on the longest size. Fold A0 in half and you will get A1. If you half an A1 sheet of paper this will become A2, all the way down to A10.

Remember, the length of the smaller size is always equal to the width of the larger size. An example is, the length of A4 is 297mm which is also the width of A3.

Other than North America and Canada, the most familiar paper size is A4 size. this is a familiar 210mm x 297mm. It is most commonly used for letters and correspondence in the UK and it is the standard paper size for most home printers. We think that most people will use a piece of A4 size paper in one form or another at least once a day.

At More Than Just Print, we print on sizes from A5 to A0, both unbound and with various binding types (as well as custom size printing if that’s what you’re looking for).

If you want to check out our online printing costs have a look at our small format (up to A3 ) printing prices here.


Here’s a comprehensive list for reference*:


What are A1 paper size dimensions?

A1 Paper size as defined by the international ISO 216 standard is 841 x 594 mm or 33.1 x 23.4 in.


What are A2 paper size dimensions?

A2 Paper size as defined by the international ISO 216 standard is 594 x 420 mm or 23.4 x 16.5 in.


What are A3 paper size dimensions?

A3 Paper size as defined by the international ISO 216 standard is 420 x 297 mm or 16.5 x 11.7 in.


What are A4 paper size dimensions?

A4 Paper size as defined by the international ISO 216 standard is 297 x 210 mm or 11.7 x 8.3 in.

What are A5 paper size dimensions?

A5 Paper size as defined by the international ISO 216 standard is 210 x 148 mm or 8.3 x 5.8 in.

What are the A6 paper size dimensions?

A6 Paper size as defined by the international ISO 216 standard is 148 x 105 mm or 5.8 x 4.1 in.

What are A7 paper size dimensions?

A7 Paper size as defined by the international ISO 216 standard is 105 x 74 mm or 4.1 x. 2.9 in.


A0 = 841×1189 mm

A1 = 594×841 mm 

A2 = 420×594 mm

A3 = 297×420 mm

A4 = 210×297 mm

A5 = 148×210 mm

A6 = 105×148 mm

A7 = 74×105 mm

*Sizes are listed width first, and then height.

A10 Paper Size A0 Paper Size

Paper Size FAQ’s

With sizes, there are some frequently asked questions, which we will try to cover below.

What size is a letterhead? ….Its A4 size

A UK letterhead would sit on an A4 sheet of paper, which is 210×297 mm.

What size is a compliment slip?

A standard UK compliment slip size is 210×99 mm. You will get three compliment slips on A4 size.

What’s a standard business card size?

A standard UK business card size is 85x55mm.

Is A3 bigger than A4 size?

A3 is twice the size of A4. The A-size number will determine the size. The lower the number, the large the size of the paper. For example, A0 is very large, whereas A8 could fit in the palm of your hand.

What’s the best size for a poster?

A0 Posters

The best size for a poster will depend on what you’ll be using it for and where you plan to display it. Posters that you’d view at a further distance should be displayed on A1, or A0 or A2. For smaller signs such as ones you might see on a notice board, it’s better to have them set on an A4 or A3 size. It’s not suggestable to design a poster on A5 or smaller, as this would be more ideal for a leaflet size.

What’s SRA3?

SRA is short for ‘supplementary raw format A’. It is slightly bigger than its corresponding A size. The slightly oversized version of the A size enables for the print to have crop marks and a bleed area which can be trimmed down.

An A3 sized paper is 420mm x 297mm. This would make SRA3 is 450mm x 320mm.

A3 is twice an A4 Size.

Getting Your Head around Paper Sizes

A simple way to get your head around A size paper is remembering if you double the edges you will always get the same width to height ratio.
A4 size paper (210mm x 297mm) folded in half will make an A5 size paper.

Fold this again, and you will have an A6 sheet.

This works through the A sizes. So if you have a large poster size A0 and it’s folded in half, you will get an A1 size. If you fold this again, you get an A2 size. It keeps going down. So the higher the number, the smaller the size. Right down to A10 size paper.

The length of the smaller size will always be the same as the width of the larger size. So for example, the length of A4 size will be the width of A3 size.

A0 Paper Size

A0 size paper is used for large format printing such as posters and signage. The A0 dimensions are 118.9 x 84.1 cms, these are “bus stop” size posters. If your looking for large posters always feel free to visit our site, we print lots of A0 posters in full vibrant colours here.

Environmentally Friendly  Paper

Whether it’s to help the environment or to meet your own ISO goals, part of an advertising campaign focused on recycling, paper is generally very eco friendly. All of the paper that we use is FSC Accredited. If you are not familiar with what FSC stands for you can read all about the Forest Stewardship Council on their webpage here.

Paper is a good choice. It comes in three levels:

Paper from controlled forests: This is paper that is produced in sustainably managed forests.

Recycled paper: Made from recycled fibres, however it does not offer the same level of whiteness as virgin paper, which can be a wise choice if your business is keen to showcase its environmental commitment to its customers.

Mixed paper: by adding virgin fibres from controlled forests to recycled fibres, however, to obtain a paper whose quality is equivalent to your usual paper while preserving the environment. To describe the thickness and the quality feel of a sheet of paper, we speak of its gram-mage, that is to say, the mass (in grams) of a sheet of 1 square meter. Furthermore, the higher the basis weight, the heavier, thicker and stronger the sheet will be. For photocopy paper, we will generally choose light and inexpensive sheets of 80 gsm in A4 size (dimensions 21 cm by 29.7 cm), whereas a magazine cover will require a gram-mage of at least 170 gsm and size of A3 paper.

History Of Paper Sizes.

The A paper sizes go all the way back to a German Scientist and Philosopher named Georg Christoph Lichtenberg.

At the start of the 20th Century, Dr Walter Portmann turned the idea into a system for standardising paper sizes. This system is still the most popular paper size system in Europe today.

More Than Just Print

I’ve never heard of More Than Just Print – how long have you been around?

More than just print launched in 2020 as an online print shop, but we’re part of The Printroom Group. We are a family run business since 1977, we have four print sites across the Thames Valley and employ over 30 staff in Bracknell, Reading and Camberley. Our clients include some of the largest companies in the world. These include Dell, Oracle Corporation and HP. Find out more about The Printroom Group.


More than just print is part of The Printroom Group – the Thames Valley’s leading family-run print business for over 40 years

To see our list of products click on our products page