Paper Size Chart (A/B Series, mm to px Converter)

Reference chart of standard paper sizes — ISO A series, JIS B series, business cards, postcards, and US Letter/Legal — in mm and px (at 96dpi and 300dpi). Includes a live mm-to-px converter.

Paper Size Reference Table (mm & px)

Category Name Size (mm) px (96dpi) px (300dpi)
ISO A series A0 841 × 1189 mm 3179 × 4494 px 9933 × 14043 px
ISO A series A1 594 × 841 mm 2245 × 3179 px 7016 × 9933 px
ISO A series A2 420 × 594 mm 1587 × 2245 px 4961 × 7016 px
ISO A series A3 297 × 420 mm 1123 × 1587 px 3508 × 4961 px
ISO A series A4 210 × 297 mm 794 × 1123 px 2480 × 3508 px
ISO A series A5 148 × 210 mm 559 × 794 px 1748 × 2480 px
ISO A series A6 105 × 148 mm 397 × 559 px 1240 × 1748 px
ISO A series A7 74 × 105 mm 280 × 397 px 874 × 1240 px
ISO A series A8 52 × 74 mm 197 × 280 px 614 × 874 px
ISO A series A9 37 × 52 mm 140 × 197 px 437 × 614 px
ISO A series A10 26 × 37 mm 98 × 140 px 307 × 437 px
JIS B series B0 1030 × 1456 mm 3893 × 5503 px 12165 × 17197 px
JIS B series B1 728 × 1030 mm 2751 × 3893 px 8598 × 12165 px
JIS B series B2 515 × 728 mm 1946 × 2751 px 6083 × 8598 px
JIS B series B3 364 × 515 mm 1376 × 1946 px 4299 × 6083 px
JIS B series B4 257 × 364 mm 971 × 1376 px 3035 × 4299 px
JIS B series B5 182 × 257 mm 688 × 971 px 2150 × 3035 px
JIS B series B6 128 × 182 mm 484 × 688 px 1512 × 2150 px
JIS B series B7 91 × 128 mm 344 × 484 px 1075 × 1512 px
JIS B series B8 64 × 91 mm 242 × 344 px 756 × 1075 px
JIS B series B9 45 × 64 mm 170 × 242 px 531 × 756 px
JIS B series B10 32 × 45 mm 121 × 170 px 378 × 531 px
Business & postal formats Business card 91 × 55 mm 344 × 208 px 1075 × 650 px
Business & postal formats Postcard 100 × 148 mm 378 × 559 px 1181 × 1748 px
Business & postal formats US Letter 215.9 × 279.4 mm 816 × 1056 px 2550 × 3300 px
Business & postal formats US Legal 215.9 × 355.6 mm 816 × 1344 px 2550 × 4200 px

Pixel values are calculated as mm ÷ 25.4 × dpi, rounded to the nearest whole number. 96dpi is the standard reference resolution for web/CSS, and 300dpi is the standard for commercial printing.

Usage Tips

  • For web design, use the 96dpi pixel values; for print production, use the 300dpi values to get a layout close to actual print size.
  • Japan's JIS B series and the ISO 216 B series differ slightly in size, so always confirm which standard a print shop abroad is using.
  • Business card and postcard sizes here follow Japanese convention; other countries often use different standard sizes (e.g. Western business cards are typically 88.9×50.8mm).
  • In the ISO A series, folding a sheet in half along its short edge always produces the next size down (A4 folded in half becomes A5, and so on).
  • US Letter is slightly wider and shorter than A4, so a PDF designed for A4 can print with shifted margins on US Letter paper.

Frequently Asked Questions

A4 (210×297mm) follows the ISO 216 standard, while US Letter (215.9×279.4mm, or 8.5×11 inches) is the North American standard. US Letter is about 6mm wider and 18mm shorter than A4, so shared templates can end up with mismatched margins.

No, they are not. Japan's JIS B series (B0 = 1030×1456mm) descends from the traditional Mino-gami paper size and differs in both area and dimensions from the ISO 216 B series (B0 = 1000×1414mm). Many overseas print services use the ISO B series, so it is worth double-checking.

Use the 96dpi pixel values for on-screen work such as websites and app UI design. For anything printed on paper — flyers, business cards, posters — use the 300dpi values, which match the resolution standard used in commercial printing.

Yes. The Japanese business card (91×55mm) and postcard (100×148mm) sizes here reflect domestic convention rather than an international standard. In Europe and North America, business cards are commonly 88.9×50.8mm (3.5×2 inches), and standard sizes vary by region.
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Side Note — the paper size born from the square root of two

The defining feature shared by every size in the ISO 216 A series is a fixed aspect ratio of 1:√2 (about 1:1.414). Fold a sheet in half along its short edge, and the resulting sheet is exactly half the area but keeps the same 1:√2 ratio — A0 folded becomes A1, A1 becomes A2, and so on. This elegant property means enlarging or reducing between sizes never wastes paper.

The √2 ratio is often credited to the German physicist and satirist Georg Christoph Lichtenberg, who described its area-preserving, self-similar property in a 1786 letter. The idea was later formalized as the German industrial standard DIN 476 in 1922, which went on to form the basis of the international standard ISO 216, adopted in 1975.

Japan's B series, by contrast, traces back to the Mino-gami paper size used for official documents in the Edo period, and developed independently of the ISO standard. That history is exactly why the JIS B series and the ISO B series differ slightly today — two standards with entirely different cultural origins that happen to share the same name.

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