Page Margin Calculations

I was trying to come up with a clever name for the title, but failed.

When designing a trade book, for example a novel, the very first thing that needs to be worked out after the page dimensions have been decided are the margins of the page. Unlike a magazine, we look at the spread of the book, ie the left and right pages together. In a left-to-right book, the right-hand page is the recto and the left-hand page is the verso.

The Spread

So with the recto and verso in front of you, you will have a spread as shown below.

Traditionally, in this arrangement, the outside margin o is twice that of the inside margin i. That means that each column of white space is equal, ie the o on the verso = 2 × i = the o on the recto.

There are various systems for calculating page margins. The arrangement above is a starting point I like to use, rather than a universal formula. The top and inside ( i ) margin are 1/9 of the width of the page and the outside ( o ) and bottom margin are double that. These values can be tweaked to fit with the grid of the page. The position of the running heads and folios (page numbers) might also affect the top and bottom margins. So for a book that has the folios and running heads at the top with nothing below, the top margin might be increased at the expense of the bottom margin. It is important that there is ample footer space, not just for aesthetic reasons, but to allow the text box to be lengthened by a line in order to align the bottom of the recto and verso (“balancing”).

The Measure

There is another factor to consider: the width of the text block, or measure. For continuous prose, an average of about 65 characters, including spaces, is a useful starting point rather than a fixed requirement. Check it with the actual typeface and size, and judge the comfort of reading at the final printed dimensions.

Sometimes, this requires reevaluating the dimensions of the book to allow appropriate margins for the text size chosen.

There is however a new factor that we have to take into account and that is of the printing process. We will address this shortly, but it is worth mentioning mass-market books where all the above concepts are thrown out of the window in favour of economy.

Pulp Fiction

Many inexpensive mass-market editions use compact layouts to limit production costs. Their narrow margins are an economic compromise, not a model that every book should follow.

The Printing Process

So, when designing a book, we also have to consider its binding. The paperback shown below is Smyth-sewn and opens relatively flat. Sewing can help a book open comfortably, but the result also depends on the paper, binding construction and other production choices.

The inside margins reflect what we would set up in InDesign. On the other hand, many paperback books will look more like this:

Note how the curvature near the spine reduces the visible inner margin. Allow for this when judging the spread, and check the printer’s binding and trimming specifications before fixing the layout. Any allowance for spine milling or other production processes should come from the printer; there is no universal amount to subtract from the inner margin.

If you have a manuscript that needs typesetting, then please contact us for a no-obligation discussion.