How Long Should a Science Fiction Novel Be, on Average?

How long should my science fiction novel be? What’s the shortest it can be—and the longest? What’s the average length for this genre? How long is too long for a sci-fi novel? And should I be counting by pages or by words?

These are common questions among first-time novel writers, and for obvious reasons. As a new writer, you want to do everything you can to increase the chance of getting your novel published someday. That includes following the norms and conventions regarding length.

So, how long should your science fiction novel be?

Most sci-fi novels fall within the range of 70,000 – 100,000 words. Some sci-fi novels run shorter, down to around 60,000 words. Epic science fiction books often go way beyond 100,000 words. But if you’re a new author and plan to pitch your novel, it might be best to stay within the average range and save the hefty tomes for later.

Ultimately, the ideal length for a science fiction novel will depend on (A) the depth and complexity of the story you want to tell and (B) the preferences of your target audience.

Ideal Length for a Science Fiction Novel

There is no standardized length for science fiction novels. They can cover a pretty wide range, as mentioned above. But there are a couple of important “bookends” you should know about, when you reach the final editing stage of your project…

Too long: If your sci-fi novel greatly exceeds the average length for such books, you might have a harder time getting it published. This is especially true for first-time writers. Literary agents might hesitate to represent a new writer with a longer-than-average science fiction novel. Longer books cost more to produce, so they’re a harder sell for publishers. A well-known writer, on the other hand, would have more leeway in this department.

Too short: If your story ends up being less than 50,000, it’s approaching novella territory. And it’s definitely a novella if it weighs in under 40,000 words. (FYI: A novella is longer than a short story, but shorter than a novel. All Systems Red, by Martha Wells is a good example.) If your story ends up within that range naturally, that’s fine. You’ve written a novella! Otherwise, find a way to make it longer so it falls within the acceptable novel length.

Some industry experts believe that 80,000 – 90,000 words is an ideal range for a debut novel, regardless of the genre. But that’s not a hard-and-fast rule. For sci-fi, a first-time author could probably go a bit longer without raising any red flags.

Here’s some good insight from fiction editor Beth Hill, courtesy of The Editor’s Blog:

“You may be the best writer to come along in years and your story may be perfect, with every one of those 130,000-plus words a necessary component, but the reality is that agents and editors have a lot of experience. And that experience has often been with overly long manuscripts that highlight not a writer’s skills but his indulgence for his own words.”

While the length is important, the quality of your writing and the overall strength of your story carry the most weight. If an agent or publisher is blown away by a story’s concept and execution, they might not pay as much attention to the length.

The Nebula Awards Model for Length

You could also use the Nebula Awards classification method to determine how long your sci-fi novel should be. Here’s how the Science Fiction and Fantasy Writers of America classifies submissions for its Nebula Awards:

• Short story: under 7,500
• Novelette: between 7,500 and 17,500
• Novella: between 17,500 and 40,000
• Novel: over 40,000

So by this yardstick, you definitely want your science fiction novel to weigh in at more than 40,000 words. Personally, I would recommend going well north of 60,000 to avoid the “too short” pitfall. If you’re story comes in at 70,000 words or more, even better.

The Nebula Awards classification system might serve as a general guide. But in reality, most sci-fi novels are a lot longer than their stated minimum of 40,000+.

Do the Work, Evaluate the Result

During the first draft, just focus on telling a great story (and having a great time). When that’s done, take a step back to evaluate the length situation. You’ll encounter one of three scenarios:

• The first draft falls within the average length range mentioned above.
• The book is a bit short and has to be lengthened with the techniques below.
• The book is way too short and would be better off marketed as a novella.

If you’re determined to write a science fiction novel—and not a novella—you might benefit from creating an outline for your story. You can measure your progress as you go, chapter by chapter, and tweak the outline as needed to reach the desired length.

Alternately, you might decide that the story works better in novella form. Be open-minded to the possibilities!

Nine Ways to Make a Sci-Fi Novel Longer

I tend to end up with shorter novels, despite my best intentions. It’s probably because I’m a pantser and not a plotter. Or maybe it’s the fact that my stories often take place within a relatively short timeframe. That’s just my inclination.

My longest book, a horror-thriller called Purgatory, weighs in at 77,500 words. But the others are shorter. I’m telling you this because, if you’re anything like me, you might struggle to get your novel up to a respectable length by science fiction standards.

The good news is, you have a lot of ways to make your book longer without sacrificing quality. Some of these techniques could also make your story better. So they perform double duty.

Here are strategies for making a science fiction novel longer:

• Character development: Spend more time digging into your characters’ backstories, motivations, inner thoughts, and inner conflicts. This will flesh out your characters while also beefing up the length of your novel. Check out my guide to creating believable characters in sci-fi for more advice in this area.
• Subplots: Consider introducing subplots that are related to the main story. Think of it as laying parallel tracks that eventually intersect. Subplots and parallel storylines can involve secondary characters or explore different aspects of the story’s world. They also increase word count.
• World-building: Expand the world you’ve created by providing more details about the setting, technology or society. In addition to lengthening the novel, this will give your readers a deeper and more satisfying experience.
• Exploring consequences: Consider the consequences of technological advancements or scientific breakthroughs within your fictional world. How do these changes affect society, politics, or the characters’ lives? Exploring them on the page can add substance to your story.
• Expanded dialogue: Look for opportunities where you might be able to expand the dialogue. You can use dialogue to give readers insight into your characters’ emotions and relationships. You can also use it to convey important information. All of which makes your sci-fi novel longer.
• Flashbacks and backstories: This technique can help you add depth and length to your novel. You can use backstories and flashbacks to develop characters, reveal secrets, or give readers additional context about the main plot. It can also help readers understand and connect with the main characters.
• Conflict and obstacles: Create new challenges and obstacles for your characters to overcome. When you think about it, most science fiction novels show the protagonist overcoming one challenge after another, leading up to the big climax. Adding conflicts and obstacles can make a science fiction longer while increasing the dramatic tension as well.
• Details and realism: Research scientific concepts or technologies relevant to your story. Incorporating real-world (or future-world) science into your story can make your sci-fi novel more engaging and believable, not to mention longer.
• Expanded ending: Consider writing a more gradual and detailed resolution of the story’s conflicts. Tie up loose ends and provide closure for subplots and character arcs. Readers like to see what happens to characters after the dust of the climax has settled. They want to know how their lives will go on. You can hint at this within your novel’s denouement or post-climax wind down.

Make Your Story as Long as It Needs to Be

Your science fiction novel should be as long as it needs to be in order to tell a good story, without burying the story in unnecessary material. You might be able to do that in 70,000 – 80,000 words, or it might take over 100,000 words. At first, just focus on the story rather than the length.

And don’t worry if your sci-fi novel ends up being more of a novella. Maybe that’s the right size for it. In that case, you could strip away the excess to create a tighter and more gripping novella-length story. You can also put out more books that way, or even create a series. Science fiction novellas are hot right now, thanks in part to writers like Martha Wells.

What did I miss? My goal is to turn this website into a valuable and useful resource for sci-fi writers like yourself. But I need your input to make that happen. Is this article missing something? Could I add something to make it more helpful? Let me know in the comments below!