Poster Sizes: How to Choose Between A4, A3 and A2

Choosing the right poster size is one of those small decisions that completely changes the way a room feels. Too small, and your poster gets lost on the wall. Too big, and it crushes everything around it. The good news: once you understand the three classic formats, A4, A3 and A2, the choice becomes simple.

In this guide, you will find the exact dimensions of each format, where each one works best, and a few easy tricks to visualise the result before you hang anything.

A4, A3 and A2: the exact dimensions

Poster sizes in the A series follow a very simple logic: each format is exactly twice the size of the previous one.

• A4: 21 x 29.7 cm. The size of a standard sheet of paper.
• A3: 29.7 x 42 cm. Twice as large as A4.
• A2: 42 x 59.4 cm. Twice as large as A3, close to a small cinema poster.

Since all three share the same proportions, you can mix them on one wall and the result stays visually consistent. That is exactly what makes the A series so practical for decorating.

A4: discreet and easy to place

A4 is the smallest of the three, and that is its strength. It slips in anywhere: on a shelf, above a desk, in a hallway, next to a mirror. It is also the ideal size to start a collection without committing to a whole wall.

On its own, an A4 poster can feel a little lost in the middle of a large empty wall. It works much better in pairs, in a row of three, or as part of a larger composition. It is also the most affordable format, which makes it perfect for testing a style before going bigger. Our best sellers are a good place to see which designs people love in this size.

A3: the best balance for most walls

If you hesitate, choose A3. It is the most versatile format: big enough to be seen from across the room, small enough to fit almost any wall. It is the classic choice for a bedroom, a home office, a corridor or the wall above a chest of drawers.

A3 is also the format that works best for album cover posters: the square artwork sits beautifully in the frame, and the details of the cover stay perfectly readable at normal viewing distance.

A2: the statement piece

A2 is the format you choose when you want the poster to be the centre of attention. Above a sofa, above the bed, or alone on a large wall, it immediately gives a room the feel of a gallery or a cinema lobby.

Keep one thing in mind: a large format needs breathing room. Leave some empty space around it and make sure you can step back two or three metres to enjoy it. In a very small room, an A2 poster can feel imposing, so check your viewing distance before you decide.

How to choose based on your room and your wall

Three simple rules will get you a result that looks professional:

• The two thirds rule. Above a piece of furniture (sofa, bed, sideboard), your poster or group of posters should cover roughly two thirds of the width of the furniture.
• Eye height. Hang your poster so its centre sits at about 1.60 m from the floor. This is the standard used in galleries, and it instantly looks right.
• Viewing distance. The further away you usually stand, the bigger the format should be. A4 is read from up close, A2 from across the room.

A simple trick: test before you buy

Not sure which size fits your wall? Cut a sheet of wrapping paper or newspaper to the exact dimensions (21 x 29.7 cm, 29.7 x 42 cm or 42 x 59.4 cm), stick it to the wall with masking tape and live with it for a day. Take a photo of the wall as well: seeing the space through your phone screen makes proportions much easier to judge.

This five minute test avoids the two classic mistakes: a poster that is too small above a large sofa, or a giant format squeezed into a narrow corner.

Mixing sizes for a gallery wall

The three formats are made to be combined. A classic layout that always works: one A2 in the centre, two A3 on the sides, and a few A4 to fill the gaps. Keep the spacing consistent (5 to 8 cm between frames) and align the centres rather than the edges.

For the frames, one simple rule keeps everything coherent: same colour, or same material. Black frames unify almost any mix. If you are looking for ideas, browse our music artist posters and imagine your three favourites side by side.

So, A4, A3 or A2?

To sum up: A4 for small spaces, compositions and first purchases. A3 for almost everything, the safest and most flexible choice. A2 for a statement piece that structures the whole room.

The most important thing is to enjoy what you hang. Take five minutes, tape a paper template to your wall, and when you are ready, most of our posters are available in A4, A3 and A2, with or without frame. Your wall deserves better than staying empty.