Z-Score & Normal Distribution Calculator
Compute standard scores (Z-scores) instantly for statistical analysis. Determine how many standard deviations a data point lies from the population or sample mean.
How to Use Z-Score & Normal Distribution Calculator
Enter Raw Score (X)
Type the individual observation or test score.
Enter Mean (μ) & Std Dev (σ)
Input the population or sample mean and standard deviation.
View Z-Score & Probability
Inspect the calculated Z-score, percentile, and normal curve placement.
About Z-Score & Normal Distribution Calculator
Calculates Z = (X - μ) / σ and estimates cumulative normal distribution probability via the error function erf(z / sqrt(2)).
Supported Formats
Operational Limits
- •Assumes normal or near-normal distribution of the underlying dataset.
Key Features
- Calculates Z = (X - μ) / σ
- Computes cumulative probability P(Z < z) and two-tailed P
- Displays percentile ranking (0% to 100%)
- Visual standard normal distribution bell curve diagram
- Clear step-by-step formula breakdown
Frequently Asked Questions
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