You can use the COUNTBLANK and COUNTA functions together in Excel to achieve a few different things. Here are two common scenarios:

1. Counting Non-Empty Cells:

* Formula: `=ROWS(range)*COLUMNS(range)-COUNTA(range)`

This formula calculates the total number of cells in a range by multiplying the number of rows by the number of columns, and then subtracts the number of non-empty cells (counted by COUNTA) to arrive at the number of blank cells (counted by COUNTBLANK indirectly).

2. Checking for Completely Blank Rows or Columns:

* You can combine COUNTBLANK with other functions and conditional formatting to identify entirely blank rows or columns.

For example, if you want to highlight rows with all blank cells:

* Apply conditional formatting to the entire data range.
* Use a formula like `=COUNTBLANK(A1:B1) = COLUMNS(A:B)` (assuming your data starts in A1 and extends to column B).
* This formula checks if the number of blank cells in the row (A1:B1) equals the total number of columns (2 in this case). If true, the entire row will be formatted as specified in your conditional formatting rule (e.g., highlighted).

Important Note:

* COUNTBLANK only counts completely empty cells, not cells containing spaces or zero-length strings. COUNTA, on the other hand, counts all non-blank cells, including those with spaces or formulas that evaluate to empty strings.