The number of books published yearly, including self-published and traditionally published books, is estimated to be between 3 million and 4 million, according to Google
Self-published books: In 2021, 2.3 million were self-published in the US.
Traditionally published books: An industry estimate is that 500,000 to 1 million new titles are published each year through a traditional publisher
In 2010, Google counted 129,864,880 unique books in the world since the invention of Gutenberg's printing press in 1440
Google estimates that there are 158,464,880 unique books worldwide as of 2023.