A-Series Paper Sizes
Complete ISO 216 A-series paper size reference: dimensions in mm, cm, inches, and pixels at standard DPIs. Used worldwide except in North America.
Physical Dimensions
| Size | Millimeters (mm) | Centimeters (cm) | Inches (in) | Common Use |
|---|---|---|---|---|
| A0 | 841 × 1189 mm |
84.1 × 118.9 cm | 33.1 × 46.8 in | Technical drawings, posters |
| A1 | 594 × 841 mm |
59.4 × 84.1 cm | 23.4 × 33.1 in | Flip charts, large posters |
| A2 | 420 × 594 mm |
42.0 × 59.4 cm | 16.5 × 23.4 in | Medium posters, diagrams |
| A3 | 297 × 420 mm |
29.7 × 42.0 cm | 11.7 × 16.5 in | Tabloid, large prints |
| A4 | 210 × 297 mm |
21.0 × 29.7 cm | 8.3 × 11.7 in | Standard documents, letters |
| A5 | 148 × 210 mm |
14.8 × 21.0 cm | 5.8 × 8.3 in | Notepads, booklets |
| A6 | 105 × 148 mm |
10.5 × 14.8 cm | 4.1 × 5.8 in | Postcards, flyers |
| A7 | 74 × 105 mm |
7.4 × 10.5 cm | 2.9 × 4.1 in | Small notepads |
| A8 | 52 × 74 mm |
5.2 × 7.4 cm | 2.0 × 2.9 in | Playing cards |
| A9 | 37 × 52 mm |
3.7 × 5.2 cm | 1.5 × 2.0 in | Stamps, labels |
| A10 | 26 × 37 mm |
2.6 × 3.7 cm | 1.0 × 1.5 in | Tiny labels |
Pixel Dimensions by DPI
| Size | 72 DPI (Web/Screen) | 150 DPI (Draft Print) | 300 DPI (Print Standard) |
|---|---|---|---|
| A0 | 2384 × 3370 px |
4967 × 7022 px |
9933 × 14043 px |
| A1 | 1684 × 2384 px |
3508 × 4967 px |
7016 × 9933 px |
| A2 | 1191 × 1684 px |
2480 × 3508 px |
4961 × 7016 px |
| A3 | 842 × 1191 px |
1754 × 2480 px |
3508 × 4961 px |
| A4 | 595 × 842 px |
1240 × 1754 px |
2480 × 3508 px |
| A5 | 420 × 595 px |
874 × 1240 px |
1748 × 2480 px |
| A6 | 298 × 420 px |
620 × 874 px |
1240 × 1748 px |
| A7 | 210 × 298 px |
437 × 620 px |
874 × 1240 px |
Understanding A-Series Paper Sizes
The √2 Ratio System
A-series paper is based on ISO 216 standard. The key principle: each size is exactly half of the previous size when folded, and all sizes have the same aspect ratio (√2:1 or 1:1.414).
How It Works
- A0: Base size with area of exactly 1 m² (841 × 1189 mm)
- A1: A0 cut in half = 594 × 841 mm
- A2: A1 cut in half = 420 × 594 mm
- A3: A2 cut in half = 297 × 420 mm
- A4: A3 cut in half = 210 × 297 mm (most common)
- A5: A4 cut in half = 148 × 210 mm
Why √2 Aspect Ratio?
When you fold a sheet in half along its longer side, it retains the same proportions. This makes scaling and printing incredibly efficient — no waste when converting between sizes.
A4 — The Global Standard
A4 (210 × 297 mm) is the most common paper size worldwide, equivalent to "Letter" size in the US (though slightly narrower and taller).
- Used in 90%+ of countries for standard documents
- At 300 DPI: 2480 × 3508 pixels
- At 150 DPI: 1240 × 1754 pixels (draft quality)
- PDF page size: 595 × 842 points (at 72 PPI)
Common Use Cases
- A0/A1: Architectural drawings, engineering plans, large format posters
- A2/A3: Posters, presentations, newspapers (A3 is tabloid size)
- A4: Office documents, letters, magazines, brochures (standard printer size)
- A5: Notepads, greeting cards, booklets (half of A4)
- A6: Postcards, flyers, invitations
Designing for Print
- Use 300 DPI for professional print quality
- Add bleed: Extend design 3mm beyond edge for trimming
- Safe zone: Keep text/logos 5mm inside margins
- CMYK color: Use CMYK, not RGB, for accurate print colors
- Embed fonts: Convert text to outlines or embed fonts in PDF
A-Series vs. US Paper
North America uses different standards:
- Letter (8.5 × 11"): Slightly wider, shorter than A4
- Legal (8.5 × 14"): Taller than Letter
- Tabloid (11 × 17"): Similar to A3 but different aspect ratio