100 Things You Should Know About People: # 91 — Size Matters When It Comes To Fonts

Diagram of parts of a font

When it comes to fonts, size matters a lot. The font size needs to be big enough so that people can read it without strain.

Not just old folks — For older people this is critical. Starting in their 40’s, most people have increasing difficulty reading small fonts. But it’s not just older people that need fonts to be bigger. I’ve conducted many usability tests on web sites and heard people in their late teens and early 20’s make spontaneous comments about the font being too small.

x-height magic — Some fonts can be the same size as others, but look bigger, due to the x-height. The x-height is literally the height of the small letter x in the font family. Look at the illustration at the top of the post to see how the x-height is measured. Different fonts have different x-heights, and as a result, some fonts look larger than others, even though they are the same font point size.

The same but not — Some of the newer font families, such as Tahoma and Verdana, have been created with large x-heights so they will be easier to read on a screen. The paragraphs below show different font families that are all the same size. Some look bigger, however, because of the larger x-height.

Examples of different fonts












What do you think? Do you have trouble reading fonts online? What font types and sizes do you use?

100 Things You Should Know About People: #92 -- There Is A Brain Area Dedicated To Perceiving Faces
100 Things You Should Know About People: #90 -- Recognition Is Easier Than Recall

18 Replies to “100 Things You Should Know About People: # 91 — Size Matters When It Comes To Fonts”

  1. While a large x-height has something to do with this, equally important is the width and letter spacing. The x-height of arial, verdana and tahoma that you show above are exactly the same, yet clearly Verdana looks a lot bigger. That’s because it uses wide characters and large letter spacing. Tahoma sort of the same as Verdana, but with less letter spacing.

  2. Thanks for posting about this issue. I see small font size as a significant issue, particularly in a business content where people are using a computer most of the day. Our organization uses a lot of vendor sites and small font size is one of the most significant complaints we get. I’ve notice that designs tend to look better when using a small font size so visual designer tend to use small fonts in their initial designs. This seems to get carried through to the final product leaving users to struggle to read in the context of doing work or servicing customers.

  3. I agree. If I have to struggle to read the font, I often click to enlarge. Printed font is also an issue and I have good vision. Personally, I stopped using the phone book to look up numbers when they reduced the size of the print so it was difficult to read easily.

    Good analogy.

  4. Pretty much the first thing I do when I encounter a new site with a fair bit of text to read is bump up the font size, because websites inevitably default to a size that’s hard to read without squinting or getting my face too close to the screen. This applies across a number of displays, from a 15″ laptop screen at 1280×800 to a 22″ desktop monitor at 1680×1050. I just don’t understand why tiny text is standard across the Web.

    …as a matter of fact, I just noticed that this site is one of those where I increased the size. :-P The default appears to be ~12px, and I got it to 19px. Of course, that broke the fixed-width layout, but I’ve learned to live with that.

  5. This confirmed what I always thought. I’m 28 and also am always increasing font sizes online. I think small font sizes online are a hangover from the print days when it was standard practice to use 12 pt text in the doc body.

  6. The other main issue people have when it comes to reading text is the low contrast that makes it doubly difficult to read, but ever so popular with designers.

    In both cases (size and contrast) it is a design concept that has nothing to do with usability and everything to do with creating a whole page artistic affect where text within a layout lines up nicely in columns or nestled against images.

    The fact that the text cannot be comfortably read by anyone is of little concern to web designers that are going to make the “balanced art” pitch to their client. “See how nice it looks when your visitor lands on the page.”

    “Oh, you wanted them to be able to read the text, gee, I thought a pretty picture would attract more visitors.”

    Yes, small and faded is the latest fad, and this site follows that fad:)

  7. Verdana is great for me, but for an old boss who was dyslexic sans serif is harder to read. Many readers depend on serifs to help orient letter direction for them. For instance the lower case letters g – and – p.

    Contrast is also an issue in web text. Too high of contrast is fatiguing as we are staring into light…I cant tell you how much I HATE white type on black background…

    And last but not least; with so many of our devices getting smaller and smaller the type is getting tiny again and for me as I age it gets harder and harder to read web content on my notebook…

  8. Absolutely true; Typography matters. We definitely want to make sure that users across the board are able to read the site or app no matter the size. It matters and if the company has a preference that matches their brand, then this takes on a whole new meaning.
    Thanks for the article, Brain Lady!

  9. Well Of course size matters when it comes to fonts. It’s the basics through which one can attract the reader.
    For eg – If your tagline is attractive, you have to write it slightly larger than the other words. Readers will pay more attention to that.
    And if you don’t want readers to focus on a particular sentence, just try to maintain the font size.

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