Why is lowercase “L” usually higher than capital “I”?

I’ve often wondered this, but I haven’t really sought an answer to it until now. Obviously, fonts do need to distinguish small “L” and capital “I” in some way and it does make sense to use letter height as a way to do so, but is there a reason why a lowercase “L” is chosen to be higher/longer than an uppercase “I”?

It just seems more logical to me that the capital letter be slightly higher.

I don’t know that this is the case for all or most sans-serif or even serif (I noticed Times New Roman does the same thing), but for Calibri it definitely is. Interestingly, Arial seems to use the same height for “I” and “l”.


The difference isn’t anything specifically to do with a lower case “L” and capital “i”, but all captials and ascenders. The short answer is they align to different metrics. There is a “Cap height” that all capital letters align to and an “ascender line” that ascenders align to.

You can see some basic font metrics, including the difference in cap and ascender heights in the typeface “Avenir” here:

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The ascender height and cap height can be the same, often the ascender height is taller than the cap height but rarely (I can’t think of any, but I won’t say never) the other way around.

One reason is readability. Capital letters are generally all the same height and easy to distinguish from lower case letter so their height isn’t an issue, the height of ascenders however can greatly affect readability, so they need to be taller—especially when there is a larger x-height—giving you more vertical variation.

It can also help in balance the visual weight of a typeface and is an important part of designing a typeface, from a purely visual perspective.

Source : Link , Question Author : Dog Lover , Answer Author : Cai

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