find size view camera

I wanted to know something. With a spell camera I can find the screen size of the device by doing Camera.main.aspect * Camera.main.orthographicSize; doing so I know where I can instantiate objects out of the screen. Can I do the same with a prospective camera? if so how?

 

EDIT: I read "screen size" and was thinking in the wrong direction. Ignore this post, sorry.

Spoiler: Original Post

Can't you use the Screen API, like Screen.width and Screen.height for example?!

Screen
https://docs.unity3d.com/ScriptReference/Screen.html

Display
https://docs.unity3d.com/ScriptReference/Display.html