I am not an expert with fonts, but I do have some experience [^exp], and common sense. This post aims to debunk some misconceptions about font sizes! [^exp]: https://github.com/nerdypepper/scientifica 11 px on your display is *probably not* 11 px on my display. Let's do some quick math. I have two displays, 1366x768 @ 21" and another with 1920x1080 @ 13", call them `A` and `B` for now. Display `A` has 1,049,088 pixels. A pixel is a square, of side say, `s` cm. The total area covered by my 21" display is about 1,066 cm^2 (41x26). Thus, ``` Display A Dimensions: 1366x768 @ 21" (41x26 sq. cm) 1,049,088 s^2 = 1066 s = 0.0318 cm (side of a pixel on Display A) ``` Bear with me, as I repeat the number crunching for Display `B`: ``` Display B Dimensions: 1920x1080 @ 13" (29.5x16.5 sq. cm) 2,073,600 s^2 = 486.75 s = 0.0153 cm (side of a pixel on Display B) ``` The width of a pixel on Display `A` is *double* the width of a pixel on Display `B`. The area occupied by a pixel on Display `A` is *4 times* the area occupied by a pixel on Display `B`. *The size of a pixel varies from display to display!* A 5x11 bitmap font on Display `A` would be around 4 mm tall whereas the same bitmap font on Display `B` would be around 1.9 mm tall. A 11 px tall character on `B` is visually equivalent to a 5 px character on `A`. When you view a screenshot of Display `A` on Display `B`, the contents are shrunk down by a factor of 2! So screen resolution is not enough, how else do we measure size? Pixel Density! Keen readers will realize that the 5^th grade math problem we solved up there showcases pixel density, or, pixels per cm (PPCM). Usually we deal with pixels per inch (PPI). **Note:** PPI is not to be confused with DPI [^dpi] (dots per inch). DPI is defined for printers. [^dpi]: https://en.wikipedia.org/wiki/Dots_per_inch In our example, `A` is a 75 ppi display and `B` is around 165 ppi [^ppi]. A low ppi display appears to be 'pixelated', because the pixels are more prominent, much like Display `A`. A higher ppi usually means you can view larger images and render crispier fonts. The average desktop display can stuff 100-200 pixels per inch. Smart phones usually fall into the 400-600 ppi (XXXHDPI) category. The human eye fails to differentiate detail past 300 ppi. *So ... streaming an 8K video on a 60" TV provides the same clarity as a HD video on a smart phone?* Absolutely. Well, clarity is subjective, but the amount of detail you can discern on mobile displays has always been limited. Salty consumers of the Xperia 1 [^sony] will say otherwise. [^sony]: https://en.wikipedia.org/wiki/Sony_Xperia_1 Maybe I will talk about font rendering in another post, but thats all for now. Don't judge a font size by its screenshot. [^ppi]: https://www.sven.de/dpi/