Choosing a poster size is a balance between visibility, content, and cost. This guide gives you a practical framework.
ISO A Sizes for Posters
| Size | Dimensions | Viewing Distance | Typical Use |
|---|---|---|---|
| A0 | 841 × 1189 mm | 3–5 m | Outdoor posters, exhibitions |
| A1 | 594 × 841 mm | 1–2 m | Conference posters, shop windows |
| A2 | 420 × 594 mm | 0.5–1 m | Academic sessions, wall posters |
| A3 | 297 × 420 mm | 0.3–0.5 m | Notice boards, small posters |
Viewing Distance and Size
Rule of thumb: body text should be readable at 1 metre for every 25 mm of cap height. If your viewer stands 3 metres away, body text needs to be at least 20–25 mm tall.
Resolution Requirements
For print, aim for 150 PPI at final size as a minimum, and 300 PPI for critical work.
| Format | 150 PPI | 300 PPI |
|---|---|---|
| A0 | 4967 × 7022 px | 9933 × 14043 px |
| A1 | 3508 × 4967 px | 7016 × 9933 px |
| A2 | 2480 × 3508 px | 4961 × 7016 px |
| A3 | 1754 × 2480 px | 3508 × 4961 px |
Cost Considerations
Poster printing cost scales with area. An A0 poster uses 4× the paper and ink of an A2. If budget is tight, choose A2 or A1. If impact is important, A0 gives the biggest presence.
Custom Poster Sizes
- 2:3 ratio — 600 × 900 mm
- 3:4 ratio — 600 × 800 mm
- Cinema ratio — 27 × 40 inches
- Bus shelter — 1185 × 1750 mm (UK) or 1200 × 1800 mm (US)
Paper and Material Options
- Standard paper — 150–200 gsm. Good for indoor posters.
- Photo paper — glossy, high-quality images.
- Canvas — durable, premium art prints.
- Vinyl — weather-resistant, outdoor.
- Foam board — mounted, rigid.
Practical Checklist
- Decide viewing distance first
- Pick the smallest A size that works
- Add 3 mm bleed on each side
- Export at 150–300 PPI
- Test print on A4 to spot typos
Frequently Asked Questions
What is the most common poster size?
A2 for wall posters; A1 for shops; A0 for large-format outdoor.
What is the best resolution for a poster?
150 PPI at final size for standard, 300 PPI for critical detail.
Can I print a poster at home?
Home printers can handle A4 or A3. For larger sizes, use a print shop.
What is bleed?
Extra margin (usually 3 mm) added around the poster to allow for trimming.
How much does poster printing cost?
From €5 for an A3 to €40+ for an A0 on premium paper.
Conclusion
Choosing the right poster size is about matching the format to the viewer, the content, and the budget.