Z-Score Calculator

Calculate the number of standard deviations a data point is from the mean

Input Data

Single Data Point

Sample Data

Data Point (x)

Sample Data

Population Mean (μ)

Population Standard Deviation (σ)

How to Use This Calculator

Select whether you’re calculating for a single data point or a sample
Enter your data values, population mean, and standard deviation
For sample data, separate values with commas, spaces, or new lines
Click “Calculate Z-Score” to see results

Z-Score Formula

For a single data point: z = (x – μ) / σ

Results

Z-Score

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Interpretation

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Probability

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Understanding Z-Scores

A z-score tells you how many standard deviations a data point is from the mean:

Positive z-score: The data point is above the mean
Negative z-score: The data point is below the mean
Z-score of 0: The data point is exactly at the mean

Common Z-Score Values

Z-Score	% Below	% Above	% Between ±Z