Z-Score Calculator

The Z-Score Calculator helps you determine how far a value is from the mean in terms of standard deviations. It’s a key tool in statistics, letting you quickly find out how unusual or typical a score is in a given distribution.

Whether you’re working with test scores, measurements, or probabilities, this tool gives you instant results and clean formatting.

Show Steps
Round Result

How to Use:

  1. Enter the Raw Score (X) you want to evaluate.
  2. Enter the Mean (μ) of your data set.
  3. Enter the Standard Deviation (σ).
  4. Use the Options toggles to:
    • Show or hide the Step-by-Step Formula
    • Enable or disable Rounded Results
  5. Output updates live and flashes whenever it changes.
  6. Export or copy the output with the buttons below. Clear everything anytime.

What Z-Score Calculator can do:

The Z-Score Calculator uses the standard formula:

Z = (X - μ) / σ

It tells you how many standard deviations a value is above or below the mean. If you turn on the “Show Steps” toggle, you’ll see the formula and numbers worked out for you. If you want cleaner results, enable the “Round Result” toggle to simplify output.

Everything updates as you type. No need to hit Enter. It just works.

Example:

Settings: Raw Score: 85, Mean: 75, Standard Deviation: 5 Show Steps: ON, Round Result: ON

Output:

Z = (X - μ) / σ
Z = (85 - 75) / 5

Z-Score = 2

Common Use Cases:

Use this tool when analyzing test scores, comparing results across different scales, or identifying outliers in data. It’s especially useful for students, teachers, data analysts, and researchers who want quick answers without crunching formulas manually.

Useful Tools & Suggestions:

Before jumping into z-scores, it’s smart to run your numbers through Calculate the Mean so you’ve got the average locked down that’s step one in any z-score formula. You might also want to try Variance Calculator since it gives you the spread of your data, which helps explain why certain values are far from the mean in the first place.

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