How many collected volumes does the Attack on Titan manga run for?

How to get close to this number

Divide the serialisation by the collection rate. The manga ran from 2009 to 2021, twelve years, and a monthly series collects roughly three volumes a year. Twelve times three gives around thirty-six, which is within a couple of the answer.

That volumes-per-year rate is the key constant for manga questions, and it depends on publication frequency: a weekly series collects four to five volumes a year, a monthly one around three. Knowing the schedule and the run length gives the volume count for any completed series.

The sales figure in the explanation is the commercial context: well over a hundred million copies in circulation including digital. Manga volumes sell in quantities that dwarf most Western publishing, and the anime adaptation questions on this site are downstream of that — the television series exists because the books sold, not the other way round.