:set showcmd

set showcmd

'showcmd' 'sc'      boolean (Vim default: on, Vi default: off)
            global
Show (partial) command in the last line of the screen.  Set this
option off if your terminal is slow.
In Visual mode the size of the selected area is shown:
- When selecting characters within a line, the number of characters.
  If the number of bytes is different it is also displayed: "2-6"
  means two characters and six bytes.
- When selecting more than one line, the number of lines.
- When selecting a block, the size in screen characters:
  {lines}x{columns}.