Why Should a Blog Post Be About 66 Characters Wide?

For blog posts and other long-form text, aim for about 66 characters per line. It is a long-established typography guideline, supported by modern usability and accessibility guidance. On the web, a width around 66ch can be a useful starting point, but the actual number of characters that fit on a line depends on the font and its settings.

Modern desktop screens keep getting larger and wider. That gives website designers much more horizontal space to work with, and it can be tempting to let a blog post expand to fill it. The result may look spacious, but a wide screen does not make very long lines of text easier to read. For continuous prose, the extra screen width is often better used as margin.

Signal v. Noise made the point neatly in its discussion of article typography: having more space in the browser window does not mean you have to fill it.

Why 66 characters?

The often-cited rule comes from typographer Robert Bringhurst. In The Elements of Typographic Style, he describes 45 to 75 characters per line as a satisfactory range for a single column of text, with 66 characters, including spaces, widely regarded as ideal.

Google’s web.dev typography guidance repeats this recommendation when discussing typography for the web.

There is good practical evidence for the same general range. Baymard Institute’s usability research recommends 50 to 75 characters per line for body text. Its testing found that overly long lines can make text appear intimidating and harder for people to read.

The reason is fairly simple. When a line becomes very long, your eyes have farther to travel across it and then farther to find the beginning of the next line. Narrowing the text column makes that repeated movement easier.

Accessibility points in the same direction

The Web Content Accessibility Guidelines also address line width.

WCAG 2.2’s Visual Presentation guidance says users should be able to achieve a line width of no more than 80 characters or glyphs. The W3C explains that long lines can make it difficult for some people with reading or vision disabilities to keep their place when moving from one line to the next.

The WCAG requirement is not a rule that every website must display text at 80 characters or fewer by default. But it reinforces the same principle: very long lines of continuous text are harder to read.

The CSS can be very simple

For a typical article, a reasonable starting point is:

.article-content {
  max-width: 66ch;
}

But 66ch does not mean that every line will contain exactly 66 characters.

The CSS ch unit is based on the width of the 0 character in the current font. It scales with the font size, which makes it more useful than a fixed pixel width for this purpose. However, normal text uses characters of many different widths: an i is much narrower than a W, for example.

Typeface, font weight, letter spacing and other typography choices also affect how many actual characters fit on a line.

So think of 66ch as a useful approximation and starting point, not as a mathematical conversion from 66 characters.

Depending on the design, you might find that 65ch, 68ch, 70ch or another nearby value produces an average line length closer to the target.

The important rule is the one expressed in characters:

Aim for roughly 66 characters per line, with about 45 to 75 being a sensible range for normal body text.

Then choose the CSS width that produces something close to that with your particular typography.

Wide screen, narrow prose

A large monitor does not mean the paragraphs need to become wider.

Images, diagrams, tables and code examples can make good use of the available screen. Article text can remain considerably narrower, with the additional space simply becoming margins.

So if you publish articles on your website or blog, there is a useful rule worth remembering:

Aim for roughly 66 characters per line, and try not to let normal body text drift much beyond 75.

It is a small design choice that can make a surprisingly large difference to how comfortable your articles are to read.