Z-Score Calculator
Published On: 20/02/2026
Z-Score Calculator
Calculate the z-score for a value using a mean and standard deviation. The z-score tells you how many standard deviations a value is above or below the mean.
Inputs explained:
• Value (x): the number you want to standardize.
• Mean (μ): the average of the distribution (population mean).
• Standard deviation (σ): how spread out the data is.
Formula: z = (x − μ) / σ.
• Value (x): the number you want to standardize.
• Mean (μ): the average of the distribution (population mean).
• Standard deviation (σ): how spread out the data is.
Formula: z = (x − μ) / σ.
Tip: If you’re working with a sample, your standard deviation is typically “s” instead of “σ”. The z-score formula is the same—just use the correct standard deviation value for your context.
Z-Score Calculator — Description
The Z-Score Calculator helps you standardize a value by converting it into a z-score. A z-score shows how far a value is from the mean, measured in standard deviations. Enter the value (x), the mean (μ), and the standard deviation (σ), and the calculator will compute z = (x − μ) / σ.
This tool is useful in statistics, test score comparisons, data normalization, and identifying how unusual a data point is relative to the rest of a distribution.