Aspect Ratio of A4 Size Paper & Digital Setup Guide
The aspect ratio of A4 size paper is 1:√2 (approximately 1:1.4142, or 210 × 297 mm). This unique mathematical ratio, defined by ISO 216, ensures that when folded in half, the sheet retains the exact same aspect ratio as A5, A3, and all A-series sizes.
A4 Document & Print Studio & Scaling Calculator
Pre-loaded with 2480 × 3508 (1:1.414portrait). Adjust width or height to calculate proportional dimensions.
Developer Outputs (CSS • HTML)Show CodeHide Code
aspect-ratio: 16 / 9;aspect-videowidth="1920" height="1080"The preview rectangle automatically scales proportionally to simulate true physical and screen viewport orientations, preventing distortion before you export.
Common 1:1.414 Resolutions & Formats
Exact pixel dimensions matching the 1:1.414 ratio across varying quality tiers.
| Standard / Tier | Dimensions (W × H) | Quality | Primary Use Case |
|---|---|---|---|
| 300 DPI (Archival / Print Master) | 2480 × 3508 px | Print Quality | Commercial offset, brochures, flyer printing |
| 150 DPI (Fast Proofing) | 1240 × 1754 px | Proof Quality | Quick office drafts and digital PDF handouts |
| 72 DPI (Web Preview) | 595 × 842 px | Screen Quality | Digital document web viewing |
Safe Zone & UI Margins
Include 3 mm bleed on all sides (216 × 303 mm canvas) for full-bleed printing.
Recommended Video & Audio Codecs
Export settings to minimize server-side recompression artifacts and preserve crisp details.
The Genius of the Lichtenberg Ratio (1:√2)
First described by physicist Georg Christoph Lichtenberg in 1786, the ratio of 1 to the square root of 2 has the unique geometric property that halving the sheet along its longest edge yields two smaller sheets with identical proportions. A4 (210×297 mm) folded in half creates two A5 sheets (148×210 mm) without distortion or wasted paper.
Frequently Asked Questions about 1:1.414
What is the aspect ratio of A4 size paper?
The aspect ratio of A4 paper is 1:√2 (approximately 1:1.4142). In millimeters, it is 210 × 297 mm. In inches, it is 8.27 × 11.69 inches.
How many pixels is an A4 page at 300 DPI?
At 300 DPI, an A4 page is 2480 × 3508 pixels. This resolution provides crisp text and photo sharpness for physical printing.
Need to calculate or inspect other aspect ratios?
Visit our universal aspect ratio calculator hub for drag-and-drop media inspection, multi-line batch processing, reverse resolution matching, and instant CSS export.
Go to Main Aspect Ratio Calculator →