Z-score Calculator
Convert a raw value to a z-score and see its position under the normal curve with one- and two-tailed probabilities.
Runs 100% in your browser — nothing is uploaded.
Runs 100% in your browser — nothing is uploaded.
Result
Z-score
2
Value relative to mean
2 σ above mean
P(X ≤ x)
97.725%
P(X > x)
2.275%
Formula
z = (x − μ) ÷ σ
About this calculator
The z-score counts how many standard deviations a value sits from the mean. Probabilities come from the standard normal distribution.
How to use
- 1
Enter the raw value, mean and standard deviation.
- 2
The z-score and tail probabilities update instantly.
Frequently asked questions
What does a z-score of 2 mean?
The value is 2 standard deviations above the mean. About 97.7% of a normal population lies below it.
Please note: Results are estimates for general information only and are not professional or medical/financial advice.