When to split into multiple books?

[T.K.]

When you're writing a manuscript, how long do you let it get before you feel like you need to split it into multiple books?

My longest novel so far clocks in at around 130,000 words. Its Kindle Edition Normalized Page Count is 553 pages. I feel like that's pushing it a bit for a single book, and if I ever write something longer than that, I would strongly consider splitting it into separate books.

Have you found any good guidelines for when a novel's length necessitates making it into multiple books? Is it up to the individual author, or does there seem to be a general consensus among writers, readers, and editors for how many words/pages is too long for a single book?

(Note that I'm not referring to stories that were planned as a multi-book series, but novels that you originally planned as a single book before they got too long.)

[Anna]

I don't think it is ever necessary but it might be advisable to keep books shorter because of the shorter attention spans people have today. We are all so busy - I am, even during lockdowns, but then, I'm a writer!

You might want to look for a comfortable place to split the story rather than dividing by the number of words.

[T.K.]

Good points!

I guess for the book I was referring to, I couldn't find what felt like a natural place to split the story. I feel like it all flowed pretty cohesively. But if I ever write something that long again, I think I'll start looking for places where it could be split.