Determining text block proportions

Established book cannon suggests a text block 2/3 the width of the page and 2/3 the height of the page where the page is in a ratio of 1:1.6. So:

• Text block width = page width x 0.66
• Text block height = page height x 0.66

Where the page doesn’t have perfect Golden proportions, you can either use the same formula, or use the following:

• Text block height = Page width
• Text block width = page width x 0.66

Determining margins

As a starting point (you will adjust for guttering and visual balance later in the process) the bottom margin should be twice the size of the top, and the outside margin twice the size of the inside one.

To calculate these:

• Total width margin = page width – text block width
• Top margin = total margin x 0.33
• Bottom margin = total margin – top margin
• Total height margin = page height – text block height
• Inside margin = total margin x 0.33
• Outside margin = total margin – top margin

The video on calculating and applying margins shows several different ways to make these calculations, but they will all bring you out with roughly the same numbers. There may be slight variations due to rounding and calculation methods, but nothing that will have a noticeable effect on the finished product.