A4 vs B5 vs 16K vs Letter: which paper size to print
A4 210×297mm, B5 176×250mm, 16K 184×260mm, Letter 216×279mm. Chinese exercise books are mostly 16K; A4 is the international default; the US uses Letter.
The numbers
A4: 210×297mm — the printer default and the size most sheet templates are designed for.
B5: 176×250mm, a step smaller, common for notebooks.
16K: 184×260mm, the main size for Chinese school exercise books.
Letter: 216×279mm — 6mm wider and 18mm shorter than A4.
Which to pick
Matching an exercise book: 16K. Binding into a booklet: A4 or B5. North American users: Letter. Unsure: A4, because it is what the printer expects.
