Paper size conversion: International versus Chinese kaiben (开本)

Chinese book sizes
In China they have a special system for book printing, which is based on dividing up an uncut sheet of paper that measures 88cm x 123cm. So dividing up the paper into 16 is called “16开” or “16开本”. So for example if you divided the paper in four, the paper size for your publication would be called 4 kai (四开). This system is complicated by the fact there is no official, universal paper size, so if someone says 8 kai or 16 kai it’s a rough guide – you must confirm with your printer the specifics. However, as a rule of thumb you can check on the following to get a rough idea of the equivalent international paper size:

Chinese term Approximate international
paper size equivalent

正度787 x 1092mm

大度 889 x 1194mm


841 x 1189mm


正度546 x 787mm

大度 597 x 889mm


594 × 841mm

四开本(4张) 4 kai

正度389 x 546mm

大度 444 x 597mm


420 x 594mm

六开本 6 kai

正度370 x 520mm

大度 285 x 420mm


297 x 420mm

八开本 8 kai

正度260 x 370mm  270 x 390mm

大度 258 x 420mm  295 x 440mm

大8开本 262 x 374mm

小8开本 260 x 368mm


297 x 420mm

十六开本 16 kai

正度185 x 260mm

大度 210 x 285mm

大16开本 187 x 262mm

小16开本 184 x 260mm


210 x 297mm

三十二开本 32 kai

正度185 x 130mm

大度 142 x 210mm

大32开本 140 x 203mm

小32开本 130 x 184mm


148 x 210mm

64开本 64 kai

大64开本 101 x 131mm  99 x 130mm

小64开本 95 x 127mm  92 x 125 mm


105 x 148mm


Image by Bromskloss

Note that where I am (China) there is a limit on large volume printing sizes: The widest they can do is 70cm (there’s no limit on length, it’s a roll of paper). So for the largest available print size, a handy size would be:

Posters: 70cm x 99cm

This is at the A series aspect ratio, roughly 1.41:1. There’s a good calculator here. Posters are often 50cm × 70cm, almost a B2 size.

1 Comment

  1. On some nice postcards bought online (the easiest way in China), I read the mention “787 x 1092 mm 1/32”. Since “787 x 1092mm” is the 正度全张 (full paper size), “1/32” means 三十二开本 (a 32-fold), so the size of my postcards is 185 x 130mm (as per your conversion table). This is not obvious. Initially I was figuring that 32张 should be 787/4 x 1092/8 = 197 x 136 mm. In fact, not. Thank you for these explanations and the conversion table.

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