Online Tool Store
Paper Size Guide
Look up A4, Letter, Legal, and other common paper sizes in millimeters, inches, and pixels at any resolution, with a scaled visual preview.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Millimeters
Inches
Pixels
| Size | mm | inches | Group |
|---|---|---|---|
| A3 | 297 × 420 mm | 11.69 × 16.54 in | ISO A |
| A4 | 210 × 297 mm | 8.27 × 11.69 in | ISO A |
| A5 | 148 × 210 mm | 5.83 × 8.27 in | ISO A |
| A6 | 105 × 148 mm | 4.13 × 5.83 in | ISO A |
| B4 | 250 × 353 mm | 9.84 × 13.90 in | ISO B |
| B5 | 176 × 250 mm | 6.93 × 9.84 in | ISO B |
| Letter | 215.9 × 279.4 mm | 8.50 × 11.00 in | US |
| Legal | 215.9 × 355.6 mm | 8.50 × 14.00 in | US |
| Tabloid | 279.4 × 431.8 mm | 11.00 × 17.00 in | US |
| Executive | 184.15 × 266.7 mm | 7.25 × 10.50 in | US |
How the paper size guide works
- Choose a paper size — ISO A/B sizes or common US sizes.
- Pick a resolution to see the equivalent pixel dimensions for screen or print use.
- The scaled preview and reference table update instantly to match your selection.
Converting millimeters to pixels
Pixel dimensions depend on resolution (dots per inch, DPI) — the same physical paper size produces more pixels at a higher DPI. To convert, first turn millimeters into inches, then multiply by the chosen DPI:
pixels = (millimeters ÷ 25.4) × DPI
Example: A4 (210 × 297 mm) at 300 DPI is (210 ÷ 25.4) × 300 = 2480 px wide and (297 ÷ 25.4) × 300 = 3508 px tall.
FAQ
What's the difference between A4 and Letter size?
A4 (210 × 297 mm) is narrower and taller than US Letter (215.9 × 279.4 mm) — A4 is standard almost everywhere outside North America, while Letter is standard in the US, Canada, and a few other countries.
How do I get an exact pixel size for print?
Choose 300 DPI, which is the standard resolution for high-quality print. For on-screen use (web graphics, presentations), 72 or 96 DPI is more typical and gives a much smaller pixel size.
Why do ISO sizes (A4, A5, …) have a clean size relationship?
Each ISO A size is exactly half the area of the size above it, cut along the long edge — A5 is half an A4, A4 is half an A3, and so on. That's why they share the same aspect ratio (1:√2) at every size.
Is Legal size the same width as Letter?
Yes — Legal is the same width as Letter (215.9 mm / 8.5 in) but taller (355.6 mm / 14 in vs. 279.4 mm / 11 in), so most printers can switch between them without adjusting paper trays.
What size is A3 in pixels at 300 DPI?
A3 (297 × 420 mm) works out to about 3508 × 4961 pixels at 300 DPI — the same 3508 px short side as A4, since A3 is exactly two A4 sheets by area.
How we compare
| Feature | Online Tool Store | papersizes.io | Wikipedia paper size table |
|---|---|---|---|
| Instant pixel size at chosen DPI | ✓ | ✓ | Manual lookup |
| Visual scaled preview | ✓ | Not shown | Not shown |
| No ads or sign-up | ✓ | Ad-supported | ✓ |
If you need an exact pixel size to design something for print, the Online Tool Store Paper Size Guide gets you the number instantly, with a visual to check it against.