Paper Size Guide — Look up dimensions for ISO A, ISO B, and US paper sizes instantly. Toggle between mm, cm, and inches. Click any row to see a visual comparison and usage details.
Visual comparison — click a row to highlight a size
| Size | Series | Width | Height | Area | Aspect Ratio | Common Use |
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About Paper Sizes
ISO A Series: The A series is the most widely used internationally. A0 has an area of exactly 1 m² with an aspect ratio of 1:√2 (≈1:1.414). Each subsequent size (A1, A2…) is half the area of the previous. A4 is the global standard for documents, letters, and forms.
ISO B Series: B sizes are the geometric mean between adjacent A sizes. Useful for posters, passports, and books where A sizes don't quite fit. B5 is common for books and notebooks.
US Sizes: Letter (8.5×11 in) is the US/Canada standard. Legal is longer for legal documents. Tabloid (11×17 in) is used for newspapers and large prints.