ISO 216 is a paper sizing system developed by the International Organization for Standardization (ISO), which is used throughout much of the world.
The width-to-height ratio of ISO 216 paper is 1:√2. This means that each piece maintains the same proportions when it is cut in half widthways, so prints can be scaled easily.
Each A-series paper size is equivalent to half the next size up, and double the next size down. For example: A3 is as large as two pieces of A4 placed side by side, while A4 is twice as large as A5.
ISO 216 Size
|
Dimensions (mm) |
Dimensions (in) |
| A0 |
841 × 1189 |
33.11 x 46.81
|
| A1 |
594 × 841 |
23.39 x 33.1
|
| A2 |
420 × 594
|
16.54 x 23.29
|
| A3 |
297 × 420
|
11.69 x 16.54
|
| A4 |
210 × 297
|
8.27 x 11.69
|
| A5 |
148 × 210
|
5.83 x 8.27
|
| A6 |
105 × 148
|
4.13 x 5.83
|
A7
|
74 × 105
|
2.91 x 4.13 |
A8
|
52 × 74
|
2.05 x 2.91 |
A9
|
37 × 52
|
1.46 x 2.05 |
A10
|
26 × 37
|
1.02 x 1.46 |
A4 is the most commonly used paper size. It is the standard format for most printers, although we do have A3 printers here at Viking — these tend to be favoured by architects, who work with large plans.
The usual format for letters, A4 paper fits into a C5 envelope when folded once or a DL envelope when folded twice. See our envelope buying guide if you need more help choosing the right envelope for different paper sizes.
GSM (grams per square metre) is a measurement of paper density, and thus an indicator of quality. Typically, the higher the GSM, the thicker, stronger and more opaque the paper.
See the table below for a general guide on the quality required for different applications:
GSM
|
Typical Usage |
| 35–55 |
Newspaper
|
| 80–90 |
Office paper
|
| 100–120 |
Professional letters
|
| 120–180 |
Posters
|
| 180–250 |
Magazine cover
|
| 250–280 |
Card-making
|
| 300 |
Leaflets
|
350–400
|
Business cards |
High-quality photo paper is around 240–280GSM, and available with a matte or gloss finish. Products are tailored to inkjet or laser printers, so make sure you buy the right type for you. It’s a good idea to buy from the same brand that manufactured your printer.
Photo paper is typically available in standard A-series sizes, so that it fits your printer, but remember that usual photo formats are not part of the ISO 216 system.
The table below lists the sizes normally offered by professional printing services. If you’re looking to frame your photos or put them in an album, you’ll have the most choice with 6 x 4 prints.
Photo Size (in)
|
Minimum ISO 216 paper size required |
| 6 x 4 |
A5
|
| 7 x 5 |
A5
|
| 8 x 6 |
A4
|
| 9 x 6 |
A4
|
| 10 x 8 |
A4
|
You can purchase books of First and Second-Class stamps for Letters or Large Letters here at Viking - perfect if you want to avoid queuing up at the Post Office.
Most printer paper comes in reams, which are normally 500 sheets each, but you can find precise information about quantities on each product page. There are also details about colour, size and other features in the specifications box.
If you are concerned about the impact your paper usage has on the environment, make sure to browse our selection of recycled paper.
