Count cells that contain numbers
Generic formula
=COUNT(rng)
Explanation
To count the number of cells that are not blank, use the COUNT function. In the generic form of the formula (above) rng represents a range of cells.
In the example, the active cell contains this formula:
=COUNT(B4:B8)
How this formula works
The COUNT function is fully automatic. It counts the number of cells in the range that contain numbers and returns the result.
Count cells that do not contain numbers
To count the number of cells in a range that do not contain numbers, use this SUMPRODUCT formula:
=SUMPRODUCT(--NOT(ISNUMBER(B4:B8)))