Poster Size Guide UK: A0, A1, A2, A3 and Custom Sizes Explained

Overview

The A-series is the most useful starting point for poster printing in the UK. Each size has a consistent proportion, making it straightforward to scale artwork between formats while preserving its layout. A0 is the largest of the common standard sizes covered here, while A3 is compact enough for smaller walls, noticeboards and countertop displays.

Standard sizes can simplify framing and make it easier to compare quotes for poster printing. However, the correct choice depends on more than the sheet measurement. Consider how far away people will stand, how much text must be read, where the poster will be displayed and whether a standard frame is important.

These dimensions are the paper size before framing, mounting or trimming. If your design needs a border, safe area or bleed, include those requirements in the artwork dimensions rather than assuming they will be added during production.

How to compare options

Start with the viewing distance

A poster intended to be read at arm’s length does not need the same scale as one placed across a busy room. Larger formats give headings and key images more presence, but size alone cannot make crowded or small type easy to read. Before ordering, stand where your audience will be and check whether the main message can be understood without moving closer.

Measure the available wall or display area

Use masking tape to mark the proposed poster on the wall. This simple reference helps reveal whether A0 or A1 will dominate a room, whether A2 will leave enough surrounding space, or whether A3 will look lost above furniture. For several posters, mark the complete arrangement, including gaps between prints and any frame edges.

Check framing and mounting requirements

Standard A sizes are often the simplest option when you want a ready-made frame or a consistent gallery wall. Custom dimensions may be better when the print must fit an existing frame, fill a narrow panel or match an unusual piece of artwork. Remember that the visible image area can be smaller than the paper size once a mount, frame or border is added.

Match the format to the content

Portrait orientation suits many event posters, portraits and vertical wall spaces. Landscape orientation can work well for panoramic photographs, timelines and wide display panels. A design with a large image and short message may scale differently from a text-heavy information poster, even when both use the same paper size.

Printable measuring reference

For a quick physical check, convert the dimensions into a temporary paper or taped outline:

• A0: mark an area 841 mm wide by 1189 mm high.
• A1: mark an area 594 mm wide by 841 mm high.
• A2: mark an area 420 mm wide by 594 mm high.
• A3: mark an area 297 mm wide by 420 mm high.

Rotate the measurements when a landscape layout is required. For reliable results, use a tape measure and check the marked area against doors, shelving, lighting and sightlines.

Feature-by-feature breakdown

A0 poster printing

A0 offers the greatest visual area in this comparison and is suited to exhibition graphics, large-format presentations and posters intended to attract attention from further away. It needs a clear wall or display position, and its weight and handling should be considered if it will be mounted temporarily. For displays exposed to frequent handling, ask whether a more rigid display material would be more suitable than paper; our guide to large format printing options explains the difference between posters, foam board and banners.

A1 poster printing

A1 is a versatile choice for event posters, retail messaging, exhibition panels and larger pieces of wall art. It has enough area for a strong image, a clear heading and supporting information without requiring an exceptionally large wall. It is often a practical middle ground when A0 feels excessive and A2 may be too small for the intended viewing distance.

A2 poster printing

A2 works well for home decor, café or studio walls, smaller promotional displays and art prints. It can provide a noticeable focal point while remaining manageable in a frame or gallery wall arrangement. It is also useful when the design has a defined central image and limited copy.

A3 poster printing

A3 is suitable for smaller promotional posters, information sheets, table displays and framed art. It is a useful supporting size alongside larger prints, particularly when you need several related pieces. For a busy venue or a message that must be read from several metres away, consider A2 or A1 instead.

Custom size poster printing

Custom size poster printing is appropriate when a standard format does not fit the space or the artwork. It can be useful for panoramic photography, narrow retail panels, bespoke welcome signs and artwork designed for a specific frame. Supply the finished width and height clearly, state the orientation and confirm whether the dimensions include any bleed or trim allowance. For artwork preparation, see our guide to preparing poster and art print files.

Size should also be considered alongside paper and finish. Matte surfaces can be easier to view where lighting creates reflections, while gloss may suit certain photographic designs. Compare the options in our matte, gloss and fine art paper guide before finalising the order.

Best fit by scenario

• Exhibition or presentation: choose A0 or A1 when the poster includes charts, artwork details or information that must be seen across a room. Check venue rules and the available mounting area first.
• Shop display: A1 is a practical starting point for prominent promotions, while A2 or A3 may suit windows, counters and smaller panels. Keep the offer, price or call to action visually clear.
• Markets, fairs and pop-ups: A1 can provide a visible headline sign; A2 and A3 are useful for product information, directions or supporting messages. Consider how the poster will be secured in changing conditions.
• Home gallery wall: A2 and A3 are easy formats to combine, although a single A1 print can anchor a larger arrangement. Plan the total wall composition rather than selecting each frame in isolation.
• Wedding welcome sign: choose a size that can be read as guests approach, then check the easel, frame or sign stand will support it. A custom size may be preferable when the display has a fixed panel.
• Art or photographic print: select the size that gives the image appropriate breathing room and matches the intended frame. For reproduction work, confirm that the source file has enough detail for the chosen dimensions.

For more specific planning, see the guides to exhibition poster printing, event poster checklists and wedding welcome signs.

When to revisit

Review this guide whenever your display conditions change, a venue introduces new size restrictions, or you move from a paper poster to a mounted or framed product. It is also worth checking the specification before each new project rather than assuming a previous order will suit a different wall, audience or viewing distance.

Before placing an order, follow this short checklist:

1. Measure the available space and mark the proposed poster size with tape.
2. Decide whether the design will be portrait or landscape.
3. Check the audience’s normal viewing distance and the amount of text.
4. Allow for borders, framing, mounting, bleed and safe areas where needed.
5. Confirm the final width and height, paper choice and finish with the printer.
6. Review a scaled proof or print a small test section if legibility is important.

If no standard A size fits the space, custom size poster printing can provide a cleaner result than forcing the artwork into the wrong proportions. The best format is the one that makes the message readable, fits the display safely and suits the way the finished print will be used.