How many episodes is your book?

From chapters to episodes

A novel is built from chapters. A television series is built from episodes. The two units rarely line up one to one, and the work of an adaptation starts with deciding which chapters belong to which episode. Get that map right and every later decision gets easier: where each episode ends, which subplot appears when, how many episodes the season needs and what the first episode has to cover.

This planner does the arithmetic. You enter the word count, the number of chapters and the episode length. It works out how many episodes the book fills, how many chapters and words each episode covers, which chapter range belongs to each episode, and where the strongest episode endings should fall.

It is a different question from how long the book would be as a single film. A film squeezes the whole book into roughly two hours, so it keeps a small share of the material. A series has many hours to fill, so it keeps much more. If you are still deciding between a film and a series, start with the movie or TV series decider and come back here once a series has won.

The one number that drives the plan

Everything in this planner comes from one figure: how many words of the book each minute of screen time covers. We call it book words per screen minute.

A high number means each minute of screen time covers a lot of the book, so the adaptation cuts hard. A low number means each minute covers only a little of the book, so the adaptation keeps more scenes and gives them room. The planner offers three settings:

These three numbers are planning settings, not published industry standards. No guild or broadcaster publishes an official figure, and real adaptations vary widely. The settings are there so you can see how the plan changes when you follow the book more or less closely. A single feature film, for comparison, usually works out well above all three, often near 800 or more book words per screen minute, because the whole novel has to fit in about two hours.

If you already know roughly how closely a producer wants to follow the book, pick the matching setting. If you do not, start with standard.

How the planner calculates the episode count

When you leave "Episodes you want" at zero, the planner chooses the number for you in three steps.

1. Screen minutes the book can fill. Divide the word count by the book words per screen minute.
2. Episodes. Divide those screen minutes by the episode length and round to the nearest whole episode.
3. Actual rate. Multiply episodes by episode length to get total screen time, then divide the word count by that total to get the rate the finished plan really uses.

The third step matters because rounding changes the rate slightly. If the book fills 5.7 episodes and the planner rounds to 6, each episode covers a little less of the book than the setting assumed. The metric labelled "Book words per screen minute" in the results shows the rate after rounding.

Worked example: a 90,000-word novel as 45-minute episodes

Take an illustrative 90,000-word novel with 30 chapters, planned as 45-minute episodes at the standard setting. These are the tool's default answers.

1. Screen minutes: 90,000 divided by 350 is about 257.1 minutes.
2. Episodes: 257.1 divided by 45 is about 5.71, which rounds to 6 episodes.
3. Total screen time: 6 times 45 is 270 minutes, or 4 hours 30 minutes.
4. Actual rate: 90,000 divided by 270 is about 333 book words per screen minute, a little gentler than the 350 setting because rounding added 13 minutes.
5. Chapters per episode: 30 divided by 6 is 5.
6. Book words per episode: 90,000 divided by 6 is 15,000.

The chapter map then follows directly. Episode 1 covers chapters 1 to 5, episode 2 covers chapters 6 to 10, and so on until episode 6 covers chapters 26 to 30. The episode breaks fall at the ends of chapters 5, 10, 15, 20 and 25.

Six episodes of about 45 minutes is a common shape for a limited series. The planner does not force that result. It falls out of the arithmetic for a book of this length.

The same book at every setting and length

Changing the setting or the episode length changes the plan a great deal. Here is the same illustrative 90,000-word, 30-chapter novel run through the planner several ways, with the episode count chosen automatically each time.

To check the faithful row by hand: 90,000 divided by 250 is 360 screen minutes, and 360 divided by 45 is exactly 8 episodes. For the half-hour row: 257.1 screen minutes divided by 30 is about 8.57, which rounds to 9. Nine half-hours make 270 minutes, the same total as six 45-minute episodes, because both round to the same screen time.

Two lessons come out of this table. First, the setting moves the episode count more than most people expect: the same book is four, six or eight episodes depending only on how closely you follow it. Second, length and count trade against each other. Four hour-long episodes and nine half-hours cover nearly the same story; the difference is how often the viewer meets an episode ending.

Decide the setting with the buyer's intent in mind. A producer who loves the book and wants readers to recognise every scene is asking for faithful. A producer who wants a fast, lean show built on the book's main plot is asking for compressed.

When there are more episodes than chapters

Short episodes change the map. Run the same 90,000-word, 30-chapter novel at 2 minutes an episode, still at the standard setting:

• 257.1 screen minutes divided by 2 is about 128.6, which rounds to 129 episodes.
• Total screen time is 129 times 2, which is 258 minutes, or 4 hours 18 minutes.
• Each episode covers 90,000 divided by 129, which is about 698 book words.
• Each chapter now spreads across about 4.3 episodes, so "chapters per episode" falls to 0.2.

In this case the table shows parts of chapters. Episodes 1 to 5 are "Ch 1 (part 1 of 5)" through "Ch 1 (part 5 of 5)". Episodes 6 to 9 split chapter 2 into four parts. The split is uneven because 129 episodes do not divide evenly into 30 chapters, so some chapters take four episodes and some take five.

The table lists the first 30 episodes and then summarises the rest, because a 129-row table is hard to read. The pattern for the remaining episodes is the same.

Two-minute episodes are the vertical micro-drama format, and they bring rules of their own: a hook in the first seconds of every episode, a twist at the end of almost every one, and a point where free viewing stops and paid viewing starts. Once you have the episode count here, the micro-drama episode planner handles that timing.

When you choose the episode count yourself

Often the number of episodes is set before the adaptation starts. A buyer may want eight episodes, or a festival series slot may allow four. Enter that number and the planner checks what it means for the book.

It works out the rate your number forces, then grades it:

The thresholds are this tool's planning rules. They mark the points where the character of the adaptation changes. Above about 600, you are no longer trimming scenes but removing storylines. Below about 150, you are no longer adapting the book but extending it.

Example: forcing the novel into four half-hours

Suppose a buyer wants the same 90,000-word novel as four 30-minute episodes. Total screen time is 4 times 30, or 120 minutes. The rate is 90,000 divided by 120, which is 750 book words per screen minute. That is above 600, so the planner warns that whole subplots must go.

The chapter map now has 7.5 chapters per episode. Because the planner keeps chapters whole when there are more chapters than episodes, episode 1 gets chapters 1 to 7, episode 2 gets chapters 8 to 15, episode 3 gets 16 to 22, and episode 4 gets 23 to 30.

Example: two 45-minute episodes

Two 45-minute episodes give 90 minutes of screen time for 90,000 words, a rate of 1,000. That is above 900, so the planner fails the plan. Ninety minutes is the length of a feature film, and a two-part split of a feature is still a feature-film adaptation. If the buyer wants two parts, plan it with film tools instead.

Example: stretching a short book

Now an illustrative 40,000-word book with 12 chapters, planned as five 60-minute episodes. That is 300 minutes of screen time, giving 133 book words per screen minute. The planner warns that the plan is thin. Five hours of television from a 40,000-word book means the writers will need to add scenes, expand minor characters or invent storylines. That can be a deliberate choice, but it should be made on purpose, not discovered halfway through writing.

Placing the cliffhangers

The map tells you where each episode ends. The next question is whether each of those endings works. A strong episode ending leaves the viewer with an open question: a threat, a reveal, a decision not yet made. A weak one lets the story come to rest, which gives the viewer a natural place to stop watching.

The planner gives each episode a target ending based on its position:

• Episode 1 ends on the inciting incident, the event that starts the main plot. This is why viewers come back for episode 2.
• The middle episode ends on a midpoint turn: a reveal that changes what the lead is trying to do. In a six-episode season, that is episode 3.
• The second-to-last episode ends on the lowest point or the biggest reveal, the moment where it looks as if the lead cannot win. In six episodes, that is episode 5.
• The last episode resolves the main story, or ends with a hook for the next season if one is planned.
• Every other episode ends on an open question that the next episode answers.

Checking the endings against your book

Go to the last page of each chapter where an episode ends. For the 90,000-word example, that means the last pages of chapters 5, 10, 15, 20 and 25. Ask one question of each: does this page leave the reader wanting to turn to the next one?

If it does, keep the break. If the chapter ends calmly, move the break to the nearest chapter that ends on a question. Moving one chapter forward or back is normal. The episode lengths will even out because screen time is spent where the story needs it, not shared out evenly by chapter.

If none of the nearby chapters end on a question, the screenwriter can create one by moving a reveal from later in the book, or by ending the episode in the middle of a chapter, at the moment before a big scene resolves.

Why chapter lengths matter

The planner assumes every chapter has about the same number of words. Many books do not. A thriller may alternate short chapters of 1,500 words with long ones of 6,000. A literary novel may have one chapter of 20,000 words.

If your chapters vary a lot, do the following:

1. List your chapters with their word counts.
2. Keep a running total down the list.
3. Find where the running total passes each multiple of the "Book words per episode" figure. For the 90,000-word example in six episodes, that is 15,000, 30,000, 45,000, 60,000 and 75,000.
4. Put each episode break at the nearest chapter ending to those points, then adjust for the strongest chapter endings as described above.

This gives each episode a similar amount of story, which is what keeps episodes from feeling rushed or padded.

Subplots across episodes

In a book, a subplot can disappear for a hundred pages and readers will wait for it. On screen, a subplot that is absent for two episodes is often forgotten. When you map chapters to episodes, check where each subplot appears.

• Mark which episodes each subplot appears in, using the chapter ranges from the table.
• If a subplot is missing from more than one episode in a row, find a short scene from a nearby chapter to carry it forward, or move one of its scenes earlier.
• If a subplot appears in only one or two episodes in total, consider cutting it or merging it into another storyline. Viewers need to see a storyline several times to care about it.

The planner's recommendations for 30- to 60-minute episodes suggest one subplot scene per episode. That is a rule of thumb for keeping subplots alive, not a rule any broadcaster enforces.

Long books, short books and series

Not every book maps to one season.

A very long book may be two seasons. Run an illustrative 180,000-word novel at the standard setting with 45-minute episodes. It fills about 514 screen minutes, which rounds to 11 episodes and 495 minutes of screen time. Eleven episodes is long for a single season of a drama. A common answer is to split the book into two seasons. Do not split at chapter 50 of 100 just because it is the halfway point. Split at the midpoint turn, the reveal that changes what the lead is trying to do, so season one ends on a question strong enough to bring viewers back.

Several short books may be one season. If each book in your series is 40,000 words, one book at the standard setting fills about 114 screen minutes, under three 45-minute episodes. A season of six to eight episodes could cover two or three books. Run the planner on the combined word count and chapter count of the books you want in the season, then check that each book's ending lands on an episode ending.

A series with books of very different lengths needs a plan per book. Run each book separately, then decide whether the short ones should share a season.

Choosing an episode length

The planner offers five lengths. Each one suits a different kind of production.

• 2 minutes. Vertical micro-drama for phones. Very many episodes, each built around one turn.
• 10 minutes. Short-form web series. Each episode holds about one main scene and one turn.
• 30 minutes. The half-hour, common for comedy and some drama. On ad-supported US television, a half-hour slot holds roughly 21 to 22 minutes of story.
• 45 minutes. A typical drama hour. On ad-supported television, a one-hour slot holds roughly 42 to 44 minutes of story; streaming dramas often run 45 to 60.
• 60 minutes. A long streaming episode with no advertising.

Broadcast story times above are common rules of thumb. The exact time depends on the network and the advertising load, so confirm the format with the buyer before you lock the plan.

If you do not know the length yet, run the planner at 45 and 30 and compare the two maps. A book that maps cleanly at one length and awkwardly at the other is telling you something about its natural rhythm.

Minutes that carry no story

Not every minute of an episode tells the story. Opening titles, a "previously on" recap and end credits all take time. On a 45-minute streaming episode they can use two or three minutes; on a 2-minute vertical episode, even ten seconds of titles is a large share.

The planner treats the whole episode length as story time, which keeps the arithmetic simple. If you know the titles, recap and credits will be long, enter a slightly shorter episode length, or choose the next setting up (standard instead of faithful) to leave room. For the same reason, many vertical series keep titles to a few seconds or drop them after the first episode.

Count words before you count anything else, too. Enter only the story text: leave out the title page, contents, acknowledgements, author's note and any sample chapter of the next book.

What this planner is not

The book to film runtime estimator answers a different question: how long the book would run as one feature film. The vertical clip planner is for short promotional clips, not a scripted series. This planner sits between them. It is for a series that tells the book's story across many episodes, from a handful of hour-long episodes to a hundred or more short ones.

It also does not write the episodes. It gives you the structure: how many, which chapters, how much story per episode and where the endings go. The writing still depends on which scenes you keep within each chapter range.

A checklist before you pitch the episode plan

• The episode count comes from the arithmetic, or you know why it differs.
• The "Book words per screen minute" figure is between 150 and 600.
• Every episode break falls at a chapter ending that leaves an open question, or you know which reveal will be moved to create one.
• The first episode ends on the inciting incident.
• The middle and second-to-last episodes end on your two strongest turns.
• Every subplot appears at least every other episode.
• If chapter lengths vary, the breaks follow running word totals, not chapter numbers.

Once the map passes this checklist, the next step is the first episode. The pilot episode planner lays it out minute by minute, using the chapter range this planner gave you for episode 1.

Sources and rules this page relies on

• Television Academy, Primetime Emmy Awards Rules and Procedures. Defines a limited series as two or more episodes with a total running time of at least 150 program minutes that tell a complete story with no ongoing storyline in later seasons. Check the current rules before you rely on the thresholds.
• Writers Guild of America West, Schedule of Minimums. Groups television programs by length for writer pay, such as 30-minute and 60-minute programs, which reflects the standard half-hour and one-hour slots behind the 30- and 45-minute options here.
• Academy of Motion Picture Arts and Sciences, Rules for the Academy Awards. Defines a feature as a film running more than 40 minutes. When this page compares a series plan with a single feature film, it means a typical feature of about two hours, not that minimum.
• Industry rules of thumb. The story times for ad-supported half-hour and one-hour slots are commonly quoted figures, not published rules, and vary by network and advertising load. Confirm with the buyer.

The three density settings (250, 350 and 500 book words per screen minute) and the grading thresholds (100, 150, 600 and 900) are this tool's own planning rules. They are not published by any of the bodies above.