判
はん · han · JLPT N3 · noun
size
📄✂️ 判 = 半 half + 刂 knife: cut a sheet in half, and you get the next size down
In Japanese, 判 (han) follows a paper or book size, as in A4判 or B5判. The left side, 半, means half, and 刂 is a knife. That fits the paper system, where each size is the one above it cut in half: A3 halved gives A4.
判 — half 半 (phonetic) + knife 刂 (semantic)
判 combines 半 'half' with 刂 'knife', literally suggesting cutting something in two. The knife radical gives the meaning of dividing or judging, while 半 provides the sound. From 'splitting apart' it extended to 'discriminate, judge, decide'.