5 min read
2026-02-25
A4 (210x297 mm) is the world standard for business documents, reports, and letters. All printers support this format.
Half an A4 sheet is a convenient format for brochures, handouts, and pocket references.
A2 (420x594 mm) — optimal size for indoor posters
A1 (594x841 mm) — for exhibition stands and large posters
Most printers don't print to the very edge. Account for 5-10 mm margins on each side.
When sending documents to the US, use Letter (216x279 mm), not A4. The difference is small but noticeable.
| Sheet | Envelope | Fold |
|---|---|---|
| A4 | C4 | No fold |
| A4 | C5/DL | Half/thirds |
| A5 | C5 | No fold |
Check sizes in the Paper Size Reference.
See also: Screen Resolution, Clothing Size Converter