So how long should each book be? There is no industry standard for how long each type of book should be, but this is a brief guide on the ideal word counts you should aim for.
Children's books are dedicated to readers between the ages of 0 and 8. The aim is those who can't read at all or who are relatively new to reading. The average number of words in this type of book is from 300 to 1200.
Most of the time, your adventure novel concentrates on both the character’s physical journey as well the journey they go through. And since it requires a trip, journey, or quest of some kind as the overall plot, the average word count for this book genre is between 90,000-130,000.
By treating love as a subplot, the main plot has nothing to do with feelings, but something completely different. Romance only adds to the plot to increase conflict or conspiracy. The average number of words in this genre is between 70,000 and 100,000.
Science fiction is currently one of the most popular types of books. With film adaptations like "Star Wars" and "The Hitchhiker's Guide to the Galaxy," this genre has exploded and appeared in the book world. Science fiction is a novel set in a future society with advanced technology and, at times, otherworldly. Depending on the storyline, the average word count for this type of book is between 60,000 and 90,000.
Self-help / Personal Development
When writing a book designed to help someone's personal life and enhance it to make positive changes, then it is probably a self-help or personal development book genre. Essentially, if the book helps others lead better lives by empowering others, then it falls into this genre which usually contains 30,000-70,000 words.