📄 A-series paper size chart
ISO A-series sizes from A0 to A10, based on a 1:√2 aspect ratio and a 1 m² A0 sheet. Centimetres are shown by default; switch units below.
A-series paper – all sizes
| Category | Size (cm) | Area | Common uses |
|---|---|---|---|
| A0 | 84.1 × 118.9 cm | 9,999.49 cm² | Office documents, Letters and reports, Everyday printing |
| A1 | 59.4 × 84.1 cm | 4,995.54 cm² | Office documents, Letters and reports, Everyday printing |
| A2 | 42 × 59.4 cm | 2,494.8 cm² | Office documents, Letters and reports, Everyday printing |
| A3 | 29.7 × 42 cm | 1,247.4 cm² | Office documents, Letters and reports, Everyday printing |
| A4 | 21 × 29.7 cm | 623.7 cm² | Office documents, Letters and reports, Everyday printing |
| A5 | 14.8 × 21 cm | 310.8 cm² | Office documents, Letters and reports, Everyday printing |
| A6 | 10.5 × 14.8 cm | 155.4 cm² | Office documents, Letters and reports, Everyday printing |
| A7 | 7.4 × 10.5 cm | 77.7 cm² | Office documents, Letters and reports, Everyday printing |
| A8 | 5.2 × 7.4 cm | 38.48 cm² | Office documents, Letters and reports, Everyday printing |
| A9 | 3.7 × 5.2 cm | 19.24 cm² | Office documents, Letters and reports, Everyday printing |
| A10 | 2.6 × 3.7 cm | 9.62 cm² | Office documents, Letters and reports, Everyday printing |
About A-series paper
ISO A-series sizes from A0 to A10, based on a 1:√2 aspect ratio and a 1 m² A0 sheet.
ISO A-series paper uses a 1:√2 aspect ratio: each size is half the area of the previous one, so A4 (210 × 297 mm) folds neatly down to A5 and enlarges to A3.
B-series paper is used for posters, books and envelopes; C-series envelopes are sized so an A4 sheet folds to fit a C5 envelope. Chinese K-sheet sizes (16K, 8K, 32K) remain common in books and notebooks.
A-series paper FAQ
What size is A4 paper?
A4 is 210 × 297 mm (21 × 29.7 cm, 8.27 × 11.69 in).
How many A4 sheets fit on A3?
Two: A3 is 297 × 420 mm, exactly twice the area of A4.