i have two dual 21" monitor and looking to go triple. what size for the middle?

[rekojenasni_787]

Hello, I can't seem to find an information where I can find a monitor size that would perfectly align with two 21" in portrait (vertical) mode while the middle monitor would stay landscape (horizontal).

So what size should I be looking at for the middle monitor that would compliment the current 21" monitors in vertical?

My current monitors are an old Dell U2211H. I would probably get a used one. Preferably the matching/same-generation model as my current to save money.

 

[igluk]

The U2211H is a 21.5 inch panel - width 18.74 inches.
So you would need 38.2 inch 16:9, 35.3 inch 16:10....or 26.5 inch 1:1 - which happens to exist in exactly this size and is called Eizo FlexScan EV2730Q..but its expensive
It also has the same PPI (102)