Use this free online Z-score calculator to determine how many standard deviations a data point (X) is from the population mean (μ). Useful for statistics, data science, and research interpretation.
📘 Formula for Z-score
Z = (X − μ) / σ
- Z: Z-score
- X: Value (data point)
- μ: Mean of the population
- σ: Standard deviation of the population
🧮 Z-score Calculator
📈 Result:
Please enter the values and click “Calculate Z-score”.
🧠 What Is a Z-score?
A Z-score (also known as a standard score) tells you how many standard deviations a value is from the mean. It’s a statistical measure used in many fields including psychology, finance, and science to identify how typical or extreme a value is in a dataset.
🔎 How to Interpret Z-scores:
- Z = 0 → Value is at the mean
- Z > 0 → Value is above the mean
- Z < 0 → Value is below the mean
- |Z| ≥ 2 → Considered statistically unusual (potential outlier)