Size or scale (6)
I believe the answer is:
extent
I believe this is a double definition.
'size' is the first definition.
(I know that extent is a type of size)
'scale' is the second definition.
(thesaurus)
(Other definitions for extent that I've seen before include "Area of coverage" , "stretch" , "reach?" , "The size or scale of something" , "Range or scope of something" .)