How Long Should Your Novel Be?

 by Thomas Kies

I’ve been reading the effusive reviews for a novel called Tom’s Crossing by Mark Z. Danielewski. The critics are ecstatic. The book was just released this month and clocks in at 1,232 pages. 

Let me repeat that.  1, 234 pages.  This isn’t official, but my rough estimate for the word count for Tom’s Crossing is 360,000.  

That’s unusual. 

When I talk with book clubs or when I teach a creative writing class, I’m often asked how long a novel should be?  The correct answer to that is a novel is as long as it needs to be to tell the story.

However, publishing is a business, and most publishers would balk at a book that stretches out over 1200 pages.  So, are there any guidelines that a writer should consider?

In traditional publishing, length is measured by word count, not page count. While pages vary depending on formatting and font, word count provides a universal yardstick.

Here’s a general breakdown for mysteries and thrillers:

• Mystery novels: 70,000–90,000 words

• Thrillers: 80,000–100,000 words

• Cozy mysteries: 65,000–80,000 words

• Police procedurals: 90,000–110,000 words

From everything I’ve read, if you’re writing your first novel, staying in the 75,000–90,000 range seems to be the sweet spot. That’s long enough to develop characters and plot twists, but short enough to keep the tension going.

The true “optimal length” of a mystery or thriller depends less on the number of words and more on the control of pacing.

A mystery builds tension like a slow burn. You want to reveal just enough information to keep readers guessing. Each chapter should add a new clue, deepen character motivation, or raise the stakes. If a scene doesn’t do one of those things, it doesn’t belong—no matter how well-written it is.

Thrillers, however, should feel like a rollercoaster ride, with moments of intense action followed by short pauses that allow readers to catch their breath. The pace dictates how long the novel feels, even more than the actual word count. A 100,000-word thriller can feel taut and fast-paced if it’s tightly constructed, while a 75,000-word story can drag if it meanders.

Readers of mysteries and thrillers have certain expectations. They know the conventions of the genre: somebody's murdered,  the sleuth digs in, the danger grows, and the climax delivers the twist or reveal. Every scene should serve a purpose—reveal character, plant a clue, or move the story forward.

I think publishers recognize this. An overly long manuscript can raise a red flag that the pacing is off or the plot needs trimming. For debut authors, staying within industry norms can make your work more marketable. Once you’re established, you earn the freedom to stretch those boundaries. Like Mark Z Danielewski.

Now, if you’re self-publishing or writing digitally, you have more leeway. Readers of e-books are often open to shorter works—novellas (30,000–50,000 words) or serialized thrillers that come out in installments. These can build a loyal audience hungry for the next episode. Still, even in the indie world, readers expect professional pacing and structure.

So, what’s the right length of a mystery or thriller?

My advice is shoot for 75,000 to 95,000 words. Ultimately, the best measure of your story’s length is whether it feels right. Does every chapter move the reader forward? Does every twist earn its place? Does the ending deliver a payoff worthy of the buildup?

If the answer is yes, then your mystery or thriller is exactly as long as it needs to be.

By the way, the longest novel ever published, according to Google, who wouldn't lie to me, is In Search of Lost Time written by Marcel Proust and printed in seven volumes clocking in at 1.3 million words.