How many pages will your book have? A castoff can tell you.

How do you estimate your page count? A castoff.

A page count estimate created before a book is actually designed is called a castoff. “Estimate” is the operative term here; castoff page counts are only estimates and will almost certainly vary from the actual, final page count. However, they are much better than guessing for the purpose of preventing unpleasant printing cost surprises late in the project. The usual process is to get printing quotes using the castoff page count, and then get revised quotes once more accurate page counts are available after page layout.

For text that runs page to page, such as the chapters of a novel or a nonfiction book, the number of pages is determined by how much text will fit on a page. How much text fits on a page in turn depends on the size of the area on the page devoted to holding text—known as the “type page”—as well as the size of the type and spacing between the lines. There are several methods for making castoffs using the number of characters in the manuscript and more or less precise estimates of the number of characters that will fit on a page:

  1. Use a rule of thumb characters-per-page value to calculate the text page count.
  2. Calculate the characters-per-page value used to figure the text page count using information about the specific typeface to be used for the book.
  3. Use our new online castoff calculator.

These methods use character counts for calculation purposes. Character counts are more accurate than word counts because the average number of characters per word varies by author, subject matter, and language. One author might have an average word length of five characters, another six: that’s a 20% difference in calculated book length! Microsoft Word and other word processing programs will give you character counts for your manuscript document. The character count should include spaces, by the way.

The List of Elements

It is good practice to make a list of all the elements in the book when you do your castoff. This helps ensure you don’t forget something, which is useful for simple books and absolutely necessary for big, complicated books. Here’s an example of a list of elements for a novel:

Element
Bastard title page
Blank
Title page
Copyright page
Dedication
Blank
Chapters
Blank
Blank
Author note
Blank
Colophon

I’ll expand upon this sample list of elements as we look at castoff calculation methods. This list, by the way, is useful not just for the castoff but as a tool in organizing the production of the book. As far as what elements your book should have and where they should go, the Chicago Manual of Style is an invaluable resource.

Castoff Method 1: Use a Character Count Rule of Thumb

Here’s a rule of thumb for calculating the amount of body text in a book based on average per-page character counts for various page sizes. This method is not as accurate as method two which uses specific font metrics, but it is better than nothing if you just need a rough estimate.

  1. Divide the total number of characters in the book by a typical number of characters per page for the planned page size.
  2. Add in one page for each chapter for the space taken up by the chapter opener and the empty portion of the page on the last chapter of the book.
  3. If the chapters are to always start on a right hand page, divide the number of chapters by two and add the result into the count.

The counts we use for this purpose are 2,400 characters per full page for a 6” x 9” book, and 2,000 characters for a 5-1/2” x 8-1/2” book. Here’s an example castoff for a novel with the relevant calculations:

Book Characteristics
Manuscript character count: 496,000
Page size: 5-1/2” x 8-1/2”
Rule of thumb characters per page: 2,000
Chapters: 13
Castoff
Element Pages  Comments
Bastard title page 1
Blank 1
Title page 1
Copyright page 1
Dedication 1
Blank 1
Chapters 248 Calculate text pages by dividing character count by characters-per-page: 496,000 ÷ 2,000 = 248
Chapter opens/ends 13
Chapters start right 7 If all chapters start right, assume half end on blank page.
Blank 1
Blank 1
Author note 1
Blank 1
Colophon 1
Total est. pages 280

By the way, I always round up when a castoff calculation results in a decimal fraction rather than down. It is much better to be surprised by a lower page count for the final book—and therefore lower printing cost —than a higher page count!

Castoff Method 2: Use a Characters-Per-Page Value Based on Typographic Data

This method is very similar to the Rule of Thumb method, but instead of using a generic per-page character count, the per-page character count is based on the spatial characteristics of an actual typeface.

Typography and the Castoff

As is generally known, type is measured not in inches, but in picas and points. A point is 1/72″, and a pica is 12 points. The “point size” of a typeface is not a precise guide to how big the letterforms actually are. As suggested above, letters of ten point Helvetica, for instance, take up about 16% more horizontal space than ten point letters of Adobe Janson. The better measure of how much space a typeface takes up is its Characters Per Pica (CPP) for a given point size. The CPP values are averages. With the CPP of a typeface and the measurements of the area taken up by type on the page—aka “type page”—you can get a pretty good estimate of how many characters will fit on a full page. A tech-savvy type house in Massachusetts, Technologies and Typography, has CPP values for many typefaces on its website here.

A type page for a novel with a 5-1/2″ x 8-1/2″ page might be 25 picas wide by 36 picas high. You want to find out how many characters of 12 point Adobe Garamond set with linespacing of 14 points will fit on this page. First let’s figure out how many lines of type will fit on a type page 34 picas high:

36 picas x 12 points per pica = 432 points

432 points / 14 points linespacing = 31 lines of type

Then let’s figure out how many characters per line on a 25-pica line with 12-point Adobe Garamond, which has a CPP of 2.37:

2.37 x 25 = 59 characters per line on average

Then, to get the number of characters per full page:

31 lines of type x 59 characters per line = 1,829 characters per page

Now, let’s revisit the castoff we created using the rule of thumb characters-per-page value:

Book Characteristics
Manuscript character count: 496,000
Page size: 5-1/2” x 8-1/2”
Calculated characters per page: 1,829 ( 2.37 CPP x 25 pica line length) X 31 lines per page = 1,829 characters per page
Chapters: 13
Castoff
Element Pages  Comments
Bastard title page 1
Blank 1
Title page 1
Copyright page 1
Dedication 1
Blank 1
Chapters 271 Calculate text pages by dividing character count by characters-per-page: 496,000 ÷ 1,829 = 271
Chapter opens/ends 13
Chapters start right 7 If all chapters start right, assume half end on blank page.
Blank 1
Blank 1
Author note 1
Blank 1
Colophon 1
Total est. pages 303

Incorporating Other Book Elements in the Castoff

Illustrations

Illustrations are typically sized as the book is designed, so the number of pages they take up cannot be calculated directly. Instead, use an average of pages per illustration to estimate the pages taken up by the illustrations. This is easy if you are devoting a full page to each illustration:

24 Illustrations @ 1 per page = 24 pages

More likely the illustrations will not take up a full page on average. In my experience about 66% of a page per illustration is a good rule-of-thumb average if the illustrations are running within the text; for some reason illustrations always take up more than you expect if you size them so they are not tiny. The need to allow room for captions probably contributes to this. So the line on the list of elements would look like this:

15 illustrations @ 66% page per illustration = 10 pages

Inserts

Sometimes, illustrations are printed in sections bound into the text pages rather than running with the text. These sections are often printed on a coated paper while the text is printed on uncoated paper. The coated paper allows for better reproduction of photos and artwork. In digital book printing, inserts can have as few as two pages; with offset printing inserts page counts are usually in multiples of eight,  because offset presses print on large sheets which are then folded into signatures containing even numbers of pages.

In a castoff, typically the insert page count is specified based on the number of illustrations and the average space factor for each:

15 illustrations and one blank = 16 pages

or

15 illustrations @ 50% page per illustration = 8 pages

There is usually a bit of trickiness in laying out inserts unless each image is given a full page, because images with a vertical aspect ratio cry out for a full page, while horizontals fit more neatly two to a page.

Tables

Because they can vary so widely in size tables are best listed individually in a castoff with an estimated space guesstimate assigned to each:

Table Book Pages
Table 1 0.50
Table 2 1.00
Table 3 0.33
Table 4 2.50
Table 5 0.50
Table 6 0.50
Total 5.33
Round up to 6.00

Notes and Other Backmatter

As these are typically set in smaller type, each of them should be calculated separately and added to the total page count. Reasonable rule-of-thumb characters per page values for notes are 3,000 characters for a 5-1/2” x 8-1/2” page and 3,500 for a 6” x 9” page.

Indexes

Indexes do not lend themselves to page calculations because they are mostly white space. Assign them 8-20 pages in the castoff depending on how long the book is.

Castoff Method 3: Use the Bookmobile Online Castoff Calculator

The Bookmobile castoff calculator allows you to specify manuscript character count, page size, margins, and typography to calculate a castoff automatically. It also allows for other elements to be added into the castoff: illustrations, tables, insert sections, etc..

Conclusion

For a simple one-column book, it shouldn’t take too long to use one of the castoff methods listed above. For more complicated books—those with lots of text, lots of chapters, lots of illustrations—it can take hours to do a proper castoff. Whether you want to invest the time depends on how important it is to you to get a relatively accurate printing cost estimate early in the project. It is those more complicated books for which printing costs can easily skyrocket, however, so if you are concerned about the budget, it is probably worth your time. Also, there are benefits other than just minimizing risk: doing the castoff is an excellent way to really think about and understand the bones of the book as you commence design and production.

Need a printing quote or more information?

I’d be happy to answer questions—you can contact me via email.
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Don Leeper is founder and CEO of Bookmobile, which has provided design, printing, eBook and distribution services for book publishers since 1982.