Enter the total proportion of the area under the curve of any data set. The calculator will convert the area of the proportion into the raw Z score.

Area to Z Score Formula

The following table is used to calculate the z score from an area.

Proportion of Area (P-Value)Z

The proportion of the area under the curve is also known as the P-value. This can be represented as a decimal or a percentage. For example, in the table above, 80% would be equal to a decimal amount of .80.

Often times this p-value is also considered to be the confidence interval. That’s because a confidence interval is a percentage of a data set that you feel is accurate.

For the use of the calculator above, you must select the P-Value from the drop-down menu, then hit calculate. The calculator will return the corresponding z-score.


What is a z score?

A z-score is a statistical value used to relate a single value to the overall mean of a group of data.

What is a p value?

A p-value is a proportion of the area or proportion of a data set used in statistical measurement.