Paper Sizes Explained: A0 to A8

1. ISO A-series paper sizes at a glance

The ISO 216 A-series is an international paper-size system based on a consistent proportion. Each size is half the area of the size immediately above it, when cut parallel to the shorter side.

For example, two A5 sheets fit within one A4 sheet, and two A4 sheets fit within one A3 sheet.

A0 to A8: dimensions and common uses

The dimensions below are the standard finished sizes, shown as width × height in millimetres in portrait orientation. Inch measurements are approximate.

These are examples, not fixed rules. The right size depends on the product, the amount of content, readability, material, intended use and production requirements. Some products also use custom dimensions rather than a standard A-series format.

2. How the A-series system works

The A-series follows a simple mathematical relationship.

• A0 has a nominal area of one square metre.
• Each successive size halves the area of the preceding size.
• The proportions remain the same, so a design can generally be scaled between A-series formats without changing its overall shape.
• The ratio of the longer side to the shorter side is approximately 1.414 to 1, or the square root of two.

This consistency is useful when resizing layouts. However, scaling artwork between sizes does not automatically make it ready for production: text size, image resolution, bleed and other specifications may still need adjustment.

3. Which paper size should you choose?

Start with the purpose of the printed product, rather than selecting a size in isolation.

For documents and reports

A4 is a practical choice for many reports, business documents and information sheets. It offers enough space for structured text, images and tables without becoming cumbersome to handle.

For brochures and marketing materials

A4 and A5 are common starting points. An A4 sheet folded in half produces four A5-sized panels when folded as a single fold, although the exact panel dimensions and layout should account for the finished construction and any production allowances.

For a compact handout, A5 or A6 may be more convenient. The choice should reflect the amount of information, intended reading distance and distribution method.

For books and publications

A-series dimensions can provide a useful starting point for book formats, but books are not restricted to them. Publishers may choose custom sizes to suit the content, design, binding, intended readership and production requirements.

Before artwork is finalised, confirm the finished book size, page count, binding method and any cover or spine specifications.

For posters and display graphics

A2, A1 and A0 offer progressively larger formats for graphics and information intended to be seen at a distance. The best size depends on viewing distance, available display space, image resolution and the dimensions supported by the chosen production method.

Large-format products may use non-A-series dimensions, so confirm the required finished size before preparing artwork.

For cards and compact printed items

A6, A7 and A8 offer smaller formats, but the smallest is not always the most practical. Text legibility, space for essential information, handling and any finishing requirements should be considered before choosing a compact size.

For labels, invitations, cards and other specialised items, a custom format may be more suitable.

4. Finished size vs sheet size: what’s the difference?

One of the most important details in a print specification is distinguishing the finished size from the size of the sheet used to produce it.

Finished size is the dimension of the product after the relevant trimming and finishing operations. For a booklet, this generally means the dimensions of the closed booklet.

Sheet size refers to the larger sheet used during printing or production. It may contain several pages or multiple copies of a design, depending on the job and production method.

The production sheet may be larger than the finished product to allow for layout, trimming, gripper margins or other process requirements. The exact arrangement depends on the equipment and specification.

When requesting a quotation, state the finished dimensions you need. If you already have a production-sheet requirement, provide that separately and confirm it with your print provider.

5. What are bleed, trim and crop marks?

If artwork extends to the edge of a printed product, the file may need to include bleed: extra artwork beyond the intended finished edge.

Trim refers to cutting the printed sheet to the required finished dimensions. Crop marks indicate the intended trim position when they are required by the production workflow.

These details help the production team understand where the finished product should be cut. Bleed requirements and file setup can vary, so confirm the specifications before submitting final artwork.

A more detailed guide to Bleed, Trim and Crop Marks is planned for this library.

6. Does paper size affect printing cost?

It can, but size alone does not determine the final price.

Cost may also depend on quantity, paper or board, printing method, colour requirements, page count, binding, finishing, packing and delivery. The way a design fits onto a production sheet can also influence material use and production efficiency.

A change in finished size may therefore affect more than the dimensions of the paper. For books, catalogues and other multi-page products, it is sensible to assess the complete specification before artwork and production plans are finalised.

7. What information should you provide to your printer?

When requesting a quotation, provide as much of the following information as you can:

• Product type: for example, a book, brochure, flyer, poster or card.
• Finished dimensions: width × height, with the orientation stated if relevant.
• Quantity: the number of finished copies required.
• Page count: for multi-page products, including any relevant cover details.
• Paper or material: if known, including weight or other preferences.
• Printing and finishing: such as colour requirements, binding, lamination or other finishes.
• Delivery destination: including any special packing or distribution requirements.

If you are unsure about some of these details, you can still begin with a description of the project and its intended use. The outstanding specifications can then be clarified before production.