A4 Size in CM, Inches, and Pixels for Printing
A4 paper size is 210 × 297 mm, 21 × 29.7 cm, or 8.27 × 11.69 inches. At 300 DPI, an A4 print needs 2480 × 3508 pixels. US Letter is 8.5 × 11 inches and needs 2550 × 3300 pixels at 300 DPI.
Direct answer
What size is A4 paper for printing?
A4 paper size is: • 210 × 297 mm • 21 × 29.7 cm • 8.27 × 11.69 inches At 300 DPI: 2480 × 3508 pixels US Letter is 8.5 × 11 inches (215.9 × 279.4 mm). At 300 DPI: 2550 × 3300 pixels.
Best for
- Checking A4 dimensions before printing posters, photos, or documents
- Choosing the right pixel size for 150 DPI or 300 DPI A4 output
- Comparing A4 with US Letter before setting up a print job
Not for
- Exact printer-safe dimensions, which vary by printer and margin settings
- Commercial large-format printing on a single oversized sheet
Works on
- A4 paper size in mm, cm, inches, and pixels
- A4 and US Letter comparison for international and North American workflows
- Poster, image, and PDF printing workflows that use regular A4 sheets
Why PrintTiler instead
- Split large images or PDFs across multiple A4 pages
- Preview page breaks and print tiled output with accurate alignment on Mac
A4 size in cm: 21 × 29.7 cm
A4 size in inches: 8.27 × 11.69 inches
In This Guide
- What Size is A4 Paper?
- A4 Size in CM, Inches, and Pixels
- A4 vs US Letter Size
- A4 Size in Pixels at Different DPI
- US Letter Size in Inches and Pixels
- Quick Answers
- What DPI Should You Use for A4 Printing?
- How Large Can You Print on A4 Paper?
- How to Print Large Posters on A4 Paper
- Printing PDFs on A4 Paper
- Common Questions
- Summary
A4 paper size is:
- 210 × 297 mm
- 21 × 29.7 cm
- 8.27 × 11.69 inches
This is the standard paper size used in most countries for printing documents, posters, and images.
What Size is A4 Paper?
A4 paper size is 210 × 297 mm (21 × 29.7 cm or 8.27 × 11.69 inches).
It is the standard paper size used in most countries outside North America.
A4 Size in CM, Inches, and Pixels
If you are checking paper measurements first, the key values are simple:
- A4 size in cm: 21 × 29.7 cm
- A4 size in inches: 8.27 × 11.69 inches
- A4 size in mm: 210 × 297 mm
A4 size can also be expressed in pixels depending on the print resolution (DPI).
A4 vs US Letter Size
US Letter is the standard office paper size in the United States and Canada. It is close to A4, but the two sizes are not interchangeable when scale, margins, or edge placement matter.
| Paper | Dimensions | Practical difference |
|---|---|---|
| A4 | 210 × 297 mm 8.27 × 11.69 in | Narrower and 17.6 mm (0.69 in) taller than Letter |
| US Letter | 215.9 × 279.4 mm 8.5 × 11 in | 5.9 mm (0.23 in) wider and shorter than A4 |
For US printers: Select Letter when 8.5 × 11 inch paper is loaded. This keeps the page grid, physical print size, and Auto Margin calculation matched to the real paper and printer.
If a PDF or sewing pattern was designed for A4, print it at 100% only on A4 paper when exact physical scale matters. Printing the same file on Letter can clip content or change its scale. For posters where the exact finished dimensions are flexible, Letter works well as long as Letter is selected in both PrintTiler and the macOS print dialog.
A4 Size in Pixels at Different DPI
At different DPI settings:
- 300 DPI -> 2480 × 3508 pixels
- 200 DPI -> 1654 × 2339 pixels
- 150 DPI -> 1240 × 1754 pixels
- 72 DPI -> 595 × 842 pixels
| DPI | Pixels | Typical use |
|---|---|---|
| 300 DPI | 2480 × 3508 pixels | Best for photos and detailed prints viewed up close |
| 200 DPI | 1654 × 2339 pixels | A practical middle ground when you want decent detail with smaller files |
| 150 DPI | 1240 × 1754 pixels | Good for posters or larger prints viewed from farther away |
| 72 DPI | 595 × 842 pixels | Only suitable for screen display, not for printing |
Higher DPI means better print quality but requires higher-resolution images.
US Letter Size in Inches and Pixels
US Letter paper is 8.5 × 11 inches, or 215.9 × 279.4 mm. It is the standard office paper size in the United States and Canada. The required pixel dimensions depend on the print resolution.
| DPI | Pixels | Typical use |
|---|---|---|
| 300 DPI | 2550 × 3300 pixels | Photos, detailed artwork, and sharp text viewed up close |
| 200 DPI | 1700 × 2200 pixels | Good detail with a more manageable source file |
| 150 DPI | 1275 × 1650 pixels | Posters and classroom materials viewed from farther away |
| 96 DPI | 816 × 1056 pixels | Screen-oriented layouts and low-resolution drafts |
| 72 DPI | 612 × 792 pixels | Screen display rather than final print output |
Before printing: Select the paper that is physically loaded in the printer. A4 and Letter are close in size, but choosing the wrong one can change the tiled grid, margins, and final physical dimensions.
Quick Answers
- What size is A4? -> 210 × 297 mm
- Is 150 DPI enough? -> Yes for posters, 300 DPI for photos
- A4 in pixels at 300 DPI? -> 2480 × 3508 px
- US Letter in pixels at 300 DPI? -> 2550 × 3300 px
What DPI Should You Use for A4 Printing?
The right DPI depends on how the print will be used.
300 DPI
Best quality
Best for photos and detailed prints viewed up close. This is the safest choice when you want clean text, sharp edges, and fine image detail on A4 paper.
Use when: Printing photos, illustrations, or anything people will inspect at arm's length.
150 DPI
Good poster quality
Good for posters or large prints viewed from a distance. It reduces file size and print time while still looking solid for wall display.
Use when: Printing posters, classroom materials, or reference prints that are not meant for close inspection.
72 DPI
Screen only
Only suitable for screen display, not for printing. On paper, this resolution usually looks soft or visibly pixelated.
Use when: You are exporting for on-screen preview rather than physical print output.
For most poster printing, 150-300 DPI is recommended. If you want a deeper explanation of how print quality changes with resolution, see our DPI and resolution settings guide.
How Large Can You Print on A4 Paper?
A4 paper is relatively small, but you can print larger images by splitting them across multiple pages.
Typical tiled poster workflow
- A poster can be printed across 4, 6, or even 9 A4 pages
- Each page prints one portion of the image
- The pages are then assembled into a larger final print
This method is often called tiled printing or poster printing.
How to Print Large Posters on A4 Paper
To print a large image across multiple A4 pages:
- Choose your target poster size.
- Split the image into multiple pages.
- Print each page at the correct scale.
- Assemble the pages together.
See our full guide onhow to print a large poster on A4 paper.
Printing PDFs on A4 Paper
Large PDF files can also be printed across multiple A4 pages.
This is especially useful for:
- Blueprints
- Maps
- Technical documents
Learnhow to print large PDF files across multiple A4 pages.
Common Questions
What size is A4 paper?
A4 is 210 × 297 mm (8.27 × 11.69 inches).
Is A4 the same as Letter size?
No. A4 is 210 × 297 mm (8.27 × 11.69 inches), while US Letter is 215.9 × 279.4 mm (8.5 × 11 inches). Letter is slightly wider and A4 is taller. Select the paper that is actually loaded in your printer, especially when exact scale or margins matter.
How many pixels is A4 at 300 DPI?
2480 × 3508 pixels.
Is 150 DPI enough for printing?
Yes for posters viewed at a distance, but 300 DPI is better for close viewing.
What is the best DPI for poster printing?
Typically 150-300 DPI depending on size and viewing distance.
Summary
Understanding A4 size, its difference from US Letter, and the required DPI is essential for getting predictable print results.
If you want to print large images or PDFs across multiple A4 pages, tools like PrintTiler can help you split and align pages accurately.
