What is aspect ratio you ask? It’s the ratio between your TV, laptop, tablet, or your phone display’s width and height. Aspect ratio is easily identified by maximum resolution of a display, if you reduce a 1080p display’s resolution 1920/1080, you get 16/9 or the aspect ratio 16:9.
So, what’s this about world full of aspect ratio? While 16:9 has dominated the display market for the past decade or so, it was never quite alone. 16:10 never quite went away, mobile market has seen both 15:9(Nokia Lumia) and 3:2(iPhone), and PC gaming is seeing a huge demand for 21:9 display in recent days. While having different aspect ratios is great for filling every niche in market, it makes it difficult to compare display sizes. A 27” 16:9 display is actually bigger than a 29” 21:9 display, a 5.7” LG V20 with a 16:9 display is bigger than a 5.7” LG G6, which has an 18:9(2:1) display or even a 5.8” Galaxy S8. And it’s not just total area, different aspect ratio also means different device width on a phone, or a different device height for a pc display.
Galaxy S8 has the same display width as a regular 5.2” display phone. A 29” 21:9 display has the same display height as a regular 23” display.
These properties actually make these great choices if they fit your need. As a matter of fact, I am writing this on a 21:9 29” display, it’s amazing for gaming. And the reduced width makes Galaxy S8 much easier to hold than its diagonal size would make you think. But the point of me writing this is that people should know what they are getting, and if you’re reading this I assume you’re the type who likes to know what you are getting.
| Diagonal | Resolution X | Resolution Y | Width | Height | Area |
| 23” | 1920 | 1080 | 20.05” | 11.28” | 226.04” |
| 27” | 2560 | 1440 | 23.53” | 13.24” | 311.50” |
| 29” | 2560 | 1080 | 26.72” | 11.27” | 301.19” |
| 5.7” | 1440 | 2560 | 2.55” | 5.10” | 13.00” |
| 5.7” | 1440 | 2880 | 2.79” | 4.97 | 13.88” |
| 5.8” | 1440 | 2960 | 2.54” | 5.22” | 13.23” |
| 5.2” | 1440 | 2560 | 2.55” | 4.53” | 11.55” |
There is a formula for that, it’s not that hard really, some basic trigonometry can get you here. All I did was make it into an easily pluggable format. You’ll remember I said that the resolution will give you the ratio, which in trig is Tangent value, so adding the diagonal to the mix we can figure out the display’s height and width. And the area is just multiplication, which looks like this,
Of course for our purpose we need separate equation for height and width. So,
Which in MS Excel terms, (SIN(ATAN(resY/resX)))*diagonal
Which in MS Excel terms, (COS(ATAN(resY/resX)))*diagonal
Happy hunting! 🙂
Simple Thoughts 