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

- Z Score Calculator
- T Statistic Calculator
- Point Estimate Calculator
- Relative Standard Deviation Calculator

## Area to Z Score Formula

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

Proportion of Area (P-Value) | Z |

80% | 1.282 |

85% | 1.44 |

90% | 1.645 |

95% | 1.96 |

99% | 2.576 |

99.50% | 2.807 |

99.90% | 3.291 |

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.

## FAQ

**What is a z score?**

A z-score is a statistical value used to related 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 a statistical measurement.