Paper Size Converter
Select a standard paper size to see its exact dimensions in inches, millimeters, and pixels (at 96 DPI) — useful when formatting documents for printing in a region or standard that differs from what you normally use.
How the Paper Size Converter formula works
Standard paper sizes are fixed, published dimensions (not calculated from a formula) defined by ISO 216 (for A-series sizes) or by regional convention (for US Letter and Legal).
Step-by-step calculation
- Select the paper size you want dimensions for.
- Read the corresponding width and height in inches, millimeters, and pixels.
Worked example
US Letter is 8.5 × 11 inches (215.9 × 279.4 mm). A4, the international standard closest in size, is 210 × 297 mm (8.27 × 11.69 inches) — close to Letter, but narrower and slightly taller, which is why documents formatted for one don't print cleanly on the other.
Frequently asked questions
Why does the US use Letter size instead of A4?
Letter size predates the international ISO 216 standard and became entrenched through longstanding US office and printing conventions, while most of the rest of the world adopted the A-series system, which is based on a consistent √2 aspect ratio across all its sizes.
What's the relationship between A4, A3, and other A-series sizes?
Each A-series size is exactly half the area of the size before it — folding an A3 sheet in half produces two A4 sheets, folding A4 in half produces A5, and so on, all sharing the same aspect ratio.