INTRODUCTION The Hidden Size Mistake Businesses Keep Making
“Are posters A3 or A2?”
It sounds like a simple question.
But here’s the twist
Most business owners pick the size based on price not visibility.
And that small decision?
It can mean the difference between people noticing your offer or walking straight past it.
If your competitor is using the right poster size and you’re not, they’re winning attention before you even get a chance.
Let’s clear this up properly.
Are Posters A3 or A2?
Short answer:
👉 Posters can be both A3 and A2 but they serve different purposes.
In the UK, poster sizes follow the A-series paper system.
Here are the dimensions:
| Size | Dimensions (mm) | Dimensions (cm) | Best For |
|---|---|---|---|
| A3 | 297 × 420 mm | 29.7 × 42 cm | Indoor notices |
| A2 | 420 × 594 mm | 42 × 59.4 cm | Events & retail displays |
Here’s what most business owners don’t realise:
A2 is twice the size of A3.
That extra space dramatically improves readability and impact.
What’s the Real Difference Between A3 and A2?
A3 Posters
✔ Affordable
✔ Easy to frame
✔ Great for internal walls
✖ Limited long-distance visibility
A3 works well for:
- Restaurant menus
- Office announcements
- Community boards
But for shop windows?
It often looks too small.
A2 Posters
✔ Stronger visual presence
✔ Readable from 2–4 metres
✔ More professional appearance
✔ Better for promotions
A2 is ideal for:
- Retail windows
- Events
- Sales promotions
- Café or salon marketing
Authority bias tells us something interesting:
Larger displays signal importance.
That’s why serious retail promotions rarely use A3 alone.
5 Benefits of Choosing the Right Size
- Better Visibility → Prevents customers walking past
- Improved Readability → Avoids cluttered design
- Stronger Brand Authority → Stops you looking “small”
- Higher Engagement → More enquiries
- Better ROI → Makes your print spend worthwhile
Loss aversion truth:
If your competitor uses A2 and you use A3 in a window display
They dominate attention.
When Should You Choose A3?
Choose A3 if:
- The poster is viewed up close (under 2 metres)
- It’s indoors
- You’re displaying multiple posters together
- Budget is tight but exposure is controlled
For internal branding, A3 can work perfectly.
When Should You Choose A2?
Choose A2 if:
- It’s for a shop window
- You need street visibility
- It’s a key promotion
- You want stronger presence
If you’re unsure about scale and readability, see our guide on which font size is best for a poster to match your text correctly to the format.
And if you’re deciding between formats, our large format printing service can recommend the most effective option before you print.
The #1 Mistake Most Businesses Make
Designing in A4 and simply “scaling up.”
Here’s the problem:
Fonts that look good at A4 may feel too small at A2.
Spacing changes.
Visual balance shifts.
Professional designers adjust hierarchy based on final size not just dimensions.
That’s why businesses working with experienced teams like Social Media Max often see better conversion from print marketing.
Before vs After
Before:
Small A3 poster in window. Hard to read. Low response.
After:
Bold A2 poster. Clear message. Increased foot traffic.
Sometimes, doubling your poster size can double your visibility.
Final Thoughts
So, are posters A3 or A2?
They can be either.
But if visibility and impact matter, A2 is usually the smarter choice for business marketing in the UK.
Poster size isn’t just paper.
It’s positioning.
👉 Ready to grow your business with professional poster printing?
Contact Social Media Max today.
Don’t wait your competitors won’t.