COUNTBLANK

Counts empty cells in a specified range of cells.
Syntax
COUNTBLANK(range)
Range    is the range from which you want to count the blank cells.
Remark
Cells with formulas that return "" (empty text) are also counted. Cells with zero values are not counted.
Example
The example may be easier to understand if you copy it to a blank worksheet.

	A	B
1	Data	Data
2
3	6	=IF(B4<30,"",B4)
4		27
5	4	34

Formula	Description (Result)
=COUNTBLANK(A2:B5)	Counts empty cells in the range above. The formula returns empty text. (4)

COUNT

Counts the number of cells that contain numbers and also numbers within the list of arguments. Use COUNT to get the number of entries in a number field that's in a range or array of numbers.
Syntax
COUNT(value1,value2,...)
Value1, value2, ...    are 1 to 30 arguments that can contain or refer to a variety of different types of data, but only numbers are counted.
Remarks

• Arguments that are numbers, dates, or text representations of numbers are counted; arguments that are error values or text that cannot be translated into numbers are ignored.
• If an argument is an array or reference, only numbers in that array or reference are counted. Empty cells, logical values, text, or error values in the array or reference are ignored. If you need to count logical values, text, or error values, use the COUNTA function.

Example