Label Autosize

Given the following code:

scrollViewVector = GUI.BeginScrollView(Rect(25, 25, 430, 220), scrollViewVector, Rect(0, 0, 400, ???));
GUI.Label(Rect(0, 0, 400, ???), "Whatever text I want here which could be short or VERY long...", thisStyle); 
GUI.EndScrollView();

Is it possible to make the label auto-size itself to however high it needs to be (???) for the text it’s displaying?

i think the only way to scale it would be through GUI.skin

probably need to use something like string.length to find out how long the text is

Not sure if this is useful to you now, but for anyone else who gets here from Google:

You’d use GUILayout (for automatic layouts) and GUI for (absolute layouts).

Source: http://forum.unity3d.com/threads/38178-what-s-the-exact-difference-between-GUI-and-GUILayout

GUIStyle.CalcSize will get you the exact space needed by an element without rendering it.

Agree, GUIStyle.CalcSize is the answer. Just a tip: you should keep the label invisible for the first frame (until you measure it), because it might give you a noticeable flicker (visible size change).