How many Harry Potter books are there?

There are 7 Harry Potter books because that's the number of books author J.K. Rowling planned and wrote for the series. The story of Harry Potter begins with "Harry Potter and the Philosopher's Stone" (or "Sorcerer's Stone" in the US) and continues through six more books, namely "Chamber of Secrets," "Prisoner of Azkaban," "Goblet of Fire," "Order of the Phoenix," "Half-Blood Prince," and finally concluding with "Deathly Hallows." This deliberate choice of 7 books allows the narrative to unfold and develop over the course of Harry's seven years at Hogwarts School of Witchcraft and Wizardry, representing a complete journey from start to finish.