Measure

The Measure menu can be found with the [Measure...] button in the main General Tool menu. Here, you can get various values and info.

The [▶Size] operation gets the total volume of the area, as well as the area dimensions (length, width, and height) of it.
The [▶Distance] operation gets the distance between the two set corner positions. The resulting value is floored.
The [▶Get Positions] operation simply gets the two selected positions.
The [Filter...] button opens a menu that lets you either search for a certain block ([Normal]), or search for all blocks except a certain block ([Exclude]). It gives you the amount of blocks found, as well as what area dimensions those blocks make up.