Does the Diary of a Wimpy Kid have 8 books or 5 in collection?

The Diary of a Wimpy Kid series has 17 books as of August 2023. There are 16 books in the main series, plus 1 spin-off book.

It seems you might be thinking about the number of books in a specific collection. Some bookstores or publishers might offer collections with 5 or 8 books, but the entire series is much larger than that.