Z-Score Calculator
Calculate z-score for statistical analysis
About this calculator
A Z-Score Calculator determines how many standard deviations a data point is from the mean in a normal distribution. This statistical tool is essential for standardizing data, comparing values across different datasets, and identifying outliers. Z-scores help researchers, students, and analysts assess the relative position of data points, calculate probabilities, and make informed decisions based on statistical significance. The calculator transforms raw data into standardized scores, making statistical analysis more meaningful and comparable.
How to use
Enter your raw data value, the population or sample mean, and the standard deviation into the respective fields. Click calculate to instantly compute the z-score. The result shows how many standard deviations your value is above or below the mean, with positive scores indicating above-average values.
Frequently asked questions
What does a negative z-score mean?
A negative z-score indicates the data point is below the mean. The larger the negative value, the further below average it is.
What is considered a high z-score?
Z-scores above +2 or below -2 are typically considered significant, representing values in the extreme 5% of the distribution.
Can I use z-scores to compare different datasets?
Yes, z-scores standardize data, allowing meaningful comparisons between datasets with different means and standard deviations.