Buzz
Every year, millions of books are published worldwide. Vladimir Melnikov/ShutterstockThe book printing and publishing industry is among the oldest in existence, sparking curiosity about the total number of books ever produced. While an exact figure remains elusive, mathematical and statistical approaches allow us to make informed estimates.
In recent years, the book publishing industry has seen tremendous growth, generating an average of around $25 billion annually and producing more than 800 million physical copies in the United States. Advancements such as e-readers and audiobooks have revolutionized the field, enabling greater content distribution while minimizing the use of physical resources.
The most significant technological breakthrough in book publishing occurred around 1440 with the invention of the Gutenberg printing press. This innovation enabled the mass production of books, replacing the laborious process of hand-copying. The press dramatically expanded book production in Europe, increasing the number of titles from a few thousand to millions, which played a key role in boosting literacy rates.
Fast forward to 2010, when Google launched a project to tally every book on the planet, identifying 129,864,880 unique titles. While this figure is staggering, it doesn't include countless books lost to history. As the catalog delves further into the past, indexed books become increasingly scarce. Google also noted that they deliberately omitted serialized pulp fiction and audio-only titles from their count.
Their data relied on titles assigned an International Standard Book Number (ISBN). The ISBN system was introduced in 1970 to help governments track book titles, meaning many pre-1970 works remain unindexed. Self-published printed books do not need to be registered in the system unless the author intends to sell them through platforms like Amazon or bookstores. (For self-published e-books, obtaining an ISBN is optional.) Typically, if a title is available in multiple formats—such as e-book, audiobook, paperback, and hardcover—it will have distinct ISBNs for each. Google stated they made efforts to eliminate duplicate entries from their count.
According to UNESCO, approximately 2.2 million new titles are published globally each year. If we estimate that 26.4 million new titles have been added since Google's 2010 count of 129,864,880, the total would reach 156,264,880 titles by 2022. This figure excludes e-books, audiobooks, and books without ISBNs, such as many self-published works. Factoring in these categories would significantly increase the total number of books worldwide.
Between 2015 and 2020, the number of self-published books in the U.S. surged by 264 percent, accounting for 43 percent of all books published during that period. However, the average self-published author sells just five copies of their book.
