NORMSINV function
Returns the inverse of the standard normal cumulative distribution. The distribution has a mean of zero and a standard deviation of one.
Important This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. Although this function is still available for backward compatibility, you should consider using the new functions from now on, because this function may not be available in future versions of Excel.
For more information about the new function, see NORM.S.INV function.
Syntax
NORMSINV(probability)
The NORMSINV function syntax has the following argument:

Probability Required. A probability corresponding to the normal distribution.
Remarks

If probability is nonnumeric, NORMSINV returns the #VALUE! error value.

If probability <= 0 or if probability >= 1, NORMSINV returns the #NUM! error value.
Given a value for probability, NORMSINV seeks that value z such that NORMSDIST(z) = probability. Thus, precision of NORMSINV depends on precision of NORMSDIST. NORMSINV uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How do I copy an example?

Select the example in this article. If you are copying the example in Excel Web App, copy and paste one cell at a time.
Important Do not select the row or column headers.
Selecting an example from Help

Press CTRL+C.

Create a blank workbook or worksheet.

In the worksheet, select cell A1, and press CTRL+V. If you are working in Excel Web App, repeat copying and pasting for each cell in the example.
Important For the example to work properly, you must paste it into cell A1 of the worksheet.

To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.
After you copy the example to a blank worksheet, you can adapt it to suit your needs.


Note The value of the result depends on the number of decimal places that are used in the number format of the cell that contains the formula.