Coming form a digital background, I have often read different kinds of suggestions (for example 35-50 ems) for how wide a column of body text should be to still maintain a good readability.

Is there any advice from the print design that could be adapted, and in what measurement are they given (em, word count, letter count, other..)? I am particularly looking for articles, books or other references on this. Can digital be mirrored to print media when it comes to column width, and vice versa?

4 Answers 4


Line lengths are usually measured in words or characters per line (or at least in my experience). I don't think print and digital are any different — the same general rules of typography apply. Short lines can create design issues and slow reading down, long lines can be unwieldy.

This study may be helpful:

This study examined the effects of line length on reading performance. Reading rates were found to be fastest at 95 cpl. Readers reported either liking or disliking the extreme line lengths (35 cpl, 95 cpl). Those that liked the 35 cpl indicated that the short line length facilitated "faster" reading and was easier because it required less eye movement. Those that liked the 95 cpl stated that they liked having more information on a page at one time. Although some participants reported that they felt like they were reading faster at 35 cpl, this condition actually resulted in the slowest reading speed.

The Effects of Line Length on Reading Online News

For slabs of body copy, I like about 70 characters per line, but anything in the 50-80 range seems good. I also think justified text is harder to read, due to the lack of unique shapes to track on the right side of text — it's far easier to lose your place.

It's also worth keeping line length in mind when designing fluid layouts. Maximum column widths are a good thing if you want to maintain legibility.

  • 2
    A good rule of thumb is to test the column width yourself. If you find yourself having to move your neck/head to read the text in a single column, then it's probably too wide. Ideally, the reader should be able to scan each line just by moving their eyes. Of course, different media/devices are read at different distances, and different people may prefer different reading distances as well, so it's not a precise science. Commented Dec 29, 2012 at 2:59
  • This begs the question of how many characters there are per em. It depends on the typeface, but there are typically (no pun intended) about 2 characters per em.
    – Heyzeuss
    Commented Aug 19, 2015 at 13:29

In traditional print media optimal line length is considered to be around 50-75 characters per line, including spaces.
Too short and you break the readers rhythm and add stress to the reading experience. Too long and you make it hard to skip from the end of one line to the correct next line.

However, studies have shown that for on screen reading the optimal line length is actually longer at around 95 characters or even higher. Also see the line length misconception.

So it would seem that no, print and digital are actually different and should not be mirrored. This would also argue the point that fluid web layouts should be avoided.

Bear in mind that readability is not just about line length.

  • Link to study is dead.
    – klaar
    Commented Mar 12, 2018 at 15:03

While studies have been done on text readability, most are inconclusive, some are contradictory, and, in general, there isn't a lot of it out there.

Line length is but one factor in the overall readability of a column of text. So it's hard to judge it on its own.

You also have to take into account:

  • the typeface being used
  • the leading (line-spacing)
  • margins
  • context (newspaper? Billboard?)

The best solution, IMHO, is to read what you design. Often we as designers can get hung up on the overall look of something and forget to actually test the usability of it ourselves.


Yes there are some nice recomendations e.g. http://desktoppub.about.com/cs/finetypography/ht/line_length.htm

and attempts to convert knowledge from printed to online typography http://www.pearsonified.com/2011/12/golden-ratio-typography.php

but universal ideal is not right question as for first the ideal depends on type of text (heavy scientific vs novel) font, line-height(!) and for the second we don't have control over number of letters per line.

  • 4
    Just a note that there really is nothing conclusive about using the golden ratio. It's more blog fodder than anything.
    – DA01
    Commented Sep 7, 2014 at 3:07
  • 1
    Using CSS, there is a way to control the number of letters per line. Example: max-width: 45em; Commented Jan 28, 2020 at 12:19

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