Paper sizes
Paper Sizes for Print Products – Paper Size Guide
This guide helps you quickly understand the most common paper sizes used in print products and their typical purposes. Easy to compare – easy to choose the right size for your brochure, poster, or business card.
How do paper sizes work? (ISO 216 explained)
In Finland, the most common paper sizes are based on the ISO 216 standard (A and B series). The logic is simple: each size is always half of the previous one, while keeping the same proportions. That’s why an A4 layout can be reduced to A5 or enlarged to A3 without distortion.
- A4 is standard office paper (210 × 297 mm).
- A5 is half of A4 (148 × 210 mm) – a handy brochure size.
- A3 is double A4 (297 × 420 mm) – a small poster format.
A Series – standard sizes for brochures and documents
| Size | Dimensions (mm) | Typical use |
|---|---|---|
| A6 | 105 × 148 | Flyers, small cards, handout marketing |
| A5 | 148 × 210 | Price lists, small brochures, program leaflets |
| A4 | 210 × 297 | Brochures, office documents, instructions |
| A3 | 297 × 420 | Posters, larger brochures, promotional prints |
An A4 sheet is the same size as standard copy paper and is the most common document format in offices.
Which A size should you choose?
- A6 – best for easy distribution (events, campaigns, point-of-sale).
- A5 – more room for content while staying compact.
- A4 – ideal for document-style brochures with lots of information.
- A3 – great for visibility (small posters, info displays).
B Series – books and special publications
| Size | Dimensions (mm) | Typical use |
|---|---|---|
| B5 | 176 × 250 | Books, notebooks, professional publications |
| B6 | 125 × 176 | Pocket books, small program leaflets |
The B series is often used in publications when a slightly more spacious format than A sizes is preferred.
Poster sizes – when you want maximum visibility
| Size | Dimensions (mm) | Where it works best |
|---|---|---|
| A0 | 841 × 1189 | Large campaign posters and exhibitions |
| A1 | 594 × 841 | Event posters, wall displays |
| A2 | 420 × 594 | Smaller posters, info signage |
| B1 | 700 × 1000 | Large indoor and outdoor advertising |
| B2 | 500 × 700 | Store and event promotional posters |
Envelope sizes (C Series) – which envelope fits A4/A5/A6?
For mailing, compatibility matters most. The C series is designed so that A-series paper fits neatly inside. Here are the most common combinations.
| Content | Envelope size | Note |
|---|---|---|
| A4 (unfolded) | C4 | For documents you don’t want to fold |
| A4 folded in half (A5) | C5 | A very common mailing size for brochures and letters |
| A4 folded into thirds (210×99mm) | C65/E65 | Traditional envelope for invoices and direct mail |
| A6 / postcard | C6 | Invitations, cards, small shipments |
If unsure, choose a slightly roomier envelope — it speeds up packing and reduces the risk of damaged corners during delivery.
Next step – choose your size and order easily
Once the size is clear, the rest is simple: choose the paper, finishing options, and upload your file. If you’re unsure, we’re happy to help you find the most practical format for your needs.
