← All tools

Paper Size Reference

Standard paper sizes at a glance — ISO 216 A, B, and C series plus North American, ANSI, and architectural formats. Each row gives exact millimetres, inches, area, and aspect ratio. Filter by name or pick a series. Runs locally in your browser.

NameSeriesmm (w × h)in (w × h)Area (m²)Ratio

ISO 216 defines the A, B, and C series with a 1∶√2 aspect ratio (≈ 0.7071), so each size folded in half yields the next. A0 is defined as 1 m²; A4 (210 × 297 mm, 8.27 × 11.69 in) is the world's default letter size. The B series sits between A sizes for posters and books; C is for envelopes (a C4 fits an unfolded A4). North American sizes (Letter 8.5 × 11 in, Legal 8.5 × 14 in, Tabloid 11 × 17 in) and the ANSI/Architectural series use inches. Inches are converted from millimetres at 25.4 mm/in and rounded for display. Runs locally — nothing leaves your browser.