Z-Score Calculator
Calculate the z-score (standard score) for a value given the mean and standard deviation.
How to Use This Calculator
Enter your values in the fields above and click "Calculate" to get instant results. This z-score calculator provides accurate results with step-by-step explanations.
Formula
z = (x - μ) / σ
Quick Examples
- x=85, μ=70, σ=10 → z=1.5
- z=1.5 → 93.32 percentile
Frequently Asked Questions
What does a z-score tell you?
A z-score tells you how many standard deviations a value is from the mean. Positive z-scores are above the mean, negative are below.
What z-score is considered significant?
In many contexts, z-scores beyond ±1.96 (corresponding to 95% confidence) are considered statistically significant.