The most common mistake when buying a poster isn’t choosing the wrong artwork – it’s choosing the wrong size. A poster that’s too small disappears against the wall and says nothing. One that’s too large takes over the room in the wrong way. The right size is the difference between a work of art that feels at home and one that looks out of place no matter how you adjust it. This guide covers all the common formats, shows you which works best where, and explains how to combine sizes in a gallery wall.
There are no universal answers – but there are clear rules of thumb that work in most homes, regardless of style or wall space.
Why choosing the right size is the most important decision you’ll make
The artwork is what you fall in love with in the store. The size is what determines whether it works in your home. Most people choose too small – out of caution, fear of taking up too much space, or because they don’t know how large they actually need. The result is a poster hanging alone on a wide wall, looking like a postage stamp.
A rule of thumb: always choose one size larger than you originally planned. You’ll never get used to a poster being too large if it otherwise fits the space – but you’ll be annoyed every day by one that’s too small. Choosing the right size from the start costs no more.
Quick facts: The three most common formats and what they’re best for: 30×40 cm works well in hallways, bathrooms, and above desks – adding detail without taking up space. 50×70 cm is the all-rounder and works in most rooms and settings. 70×100 cm is a statement size for living rooms and bedrooms where you want the poster to anchor the wall. If your wall is wider than 150 cm, always go for 70×100 cm or a composition of several 50×70 cm posters.
Which poster size works best in each room?
The right size depends on the room’s floor area, the proportions of the furniture, and how much wall space you want the poster to take up. Here’s a room-by-room guide.
In a hallway, the walls are often narrow and space is limited. 30×40 cm is the natural choice for a narrow hallway wall – it creates a considered look without taking up space. If you have a wider hallway with a wall above a table or bench, 50×70 cm is a better fit and gives the entryway more character. A single large poster in the hallway sets the mood for your whole home as soon as you walk through the door.
In the bedroom, the rule is clear: the width of the poster above the bed should be about 2/3 of the bed's width. For a 160 cm wide double bed, that means aiming for a poster or composition that covers at least 100 cm. That means one 70×100 cm print, or two 50×70 cm prints side by side. A poster that's too small above the bed never balances the room. For more on bedroom placement, see the guide posters in the bedroom.
In the living room, the wall can take more. Above a sofa (usually 180–220 cm wide), aim for a composition that covers 60–75 percent of the sofa's width - this could be a centered 70×100 cm print, or three 50×70 cm prints in a row. A single 50×70 cm print above a wide sofa always looks too small, no matter how good the design is.
30×40, 50×70 and 70×100 cm - three sizes, three looks
Each size has its own character and strengths. Understanding the difference makes it easier to choose the right one from the start.
30×40 cm is the detail size. It's ideal when you want a design you can get close to and look at - a botanical illustration with fine detail, an abstract work with subtle brushstrokes, a photograph with a story. It also works beautifully in a group: three 30×40 cm prints in a row with 5 cm between them create a clear composition with much more impact than a single poster of the same size. Cosmic Safari is a great example of a design that works beautifully in this format.
50×70 cm is the all-rounder size for a reason: it's large enough to anchor a room and small enough not to dominate it. It works just as well on its own above a desk as it does in a gallery wall with five other sizes. It's the size that works in more settings than any other, and a safe choice if you're unsure.
70×100 cm is the statement size. It should be seen, it should anchor the wall, it should be the first thing you notice when you enter the room. Choosing 70×100 cm means choosing a work that takes up space - and that's the point. Wet Strawberries is a design that really makes the most of the large format's vibrancy. Abstract designs with movement and bold colors generally work well in this format.
"The only mistake with format that's hard to live with is going too small. You can always work with a poster that's a little too large. One that's too small reminds you every day."
How do you combine different poster sizes on a gallery wall?
A mixed-format gallery wall adds dynamism and personality - but requires more planning than a wall with a single large format. There's a simple way to approach it: choose an anchor piece and build around it.
The anchor piece is the piece that holds the composition together - usually the largest format, 70×100 cm or 50×70 cm, placed in the center. Hang smaller formats around it: a 30×40 cm piece on the left, a 50×70 cm piece on the right, a 21×30 cm piece in a corner. What ties the composition together isn't the sizes - it's the cohesive palette or theme.
Tip: Lay out all the posters on the floor in your planned arrangement before drilling a single hole. Take a photo from above with your phone and review it - it's much easier to see whether the proportions and balance work in a photo than when you're standing in front of the wall. Rearrange them until it feels right, mark the positions with masking tape, and drill last.
A classic three-piece combination is 30×40 + 50×70 + 30×40 cm in a row, with matching frames and a cohesive theme. It creates movement without chaos. Find out more about planning a gallery wall in the complete gallery wall guide.
Which frame suits which format?
The frame creates cohesion - and the format affects which frame works best.
For 30×40 cm: choose a frame with a slimmer profile. A wide, heavy frame takes up a disproportionate amount of visual space around a small format and makes the artwork fade into the background. A slim oak frame or a thin black metal frame lets the artwork take center stage. A mat - a white or cream-colored board inside the frame - is an excellent way to give a small format extra gallery impact and more visual weight.
For 50×70 cm: you have more freedom here. All frame types work - choose based on the artwork and the room. A wider walnut frame adds weight and warmth to a soft botanical print. A slim black metal frame gives an abstract or photographic work a modern, graphic look.
For 70×100 cm: the frame is part of the design, not just a border. With a large size, the frame actively contributes to the room’s character. A wide oak or walnut frame can be the only wooden element in a room and still fit in. See the full range of wooden frames and metal frames in all sizes and styles.
Explore Bozetto’s full range of posters – all standard sizes from 13×18 cm to 100×140 cm.
Frequently asked questions about poster sizes
What size poster should you hang above the sofa?
The composition above the sofa should cover 60–75 percent of its width. For a 200 cm wide sofa, aim for a total width of at least 120–150 cm – that could be a centered 70×100 cm poster or three 50×70 cm posters in a row. A single 50×70 cm poster above a wide sofa almost always looks too small.
What is the most popular poster size?
50×70 cm is the best-selling size for a clear reason: it’s large enough to anchor a room and small enough not to dominate it. It works in most rooms and settings and is a safe choice if you’re unsure what will fit.
Can you mix different poster sizes?
Yes – and it often creates the most dynamic and personal gallery wall. The key is to have an anchor piece in the largest size, which the composition is built around, and a unified palette or theme that ties the different sizes together.
Which size works best in the hallway?
30×40 cm for narrow hallway walls. 50×70 cm if you have a wider space or want your hallway to have more character. Avoid 70×100 cm in a narrow hallway – it takes up a disproportionate amount of space and makes the entrance feel cramped rather than welcoming.
How do you choose a frame for the right poster size?
Simple rule: narrower frame for smaller sizes, more flexibility for larger sizes. For 30×40 cm: choose a slim profile and consider a mat. For 50×70 cm: any frame type works. For 70×100 cm: the frame can be wide and contribute to the room’s character. Always keep the frame color consistent if you have several posters on the same wall.