Z-Score
Calculator

Calculate z-scores from raw values or find raw values from z-scores. Includes percentile and interpretation for standard normal distribution.

Mode

Input

Z-Score

-1.0000

Percentile
15.87%
Interpretation
Between 1 and 2 standard deviations from the mean

Learn more

How do z-scores let you compare values across different scales?

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Frequently Asked Questions

A z-score (also called a standard score) indicates how many standard deviations a value is above or below the mean of a distribution. A z-score of 0 means the value equals the mean; positive values are above the mean and negative values are below.

Subtract the population mean from the observed value and divide by the standard deviation. The formula is z equals (x minus mu) divided by sigma, where x is the data point, mu is the mean, and sigma is the standard deviation.

Z-scores are used to compare values from different distributions, identify outliers, and calculate probabilities using the standard normal distribution table. They are common in hypothesis testing and quality control.

Z-Score Calculator - Calculate Z-Scores and Percentiles | ToolsCanvas