Statistics
Z-Score Calculator
Enter your raw score, the mean, and the standard deviation to convert it into a standardized Z-score with percentile rank.
Z-score
+0.7500
Your score is above the mean and within 1 standard deviation of the mean.
Percentile rank
77.34%
of scores are lower
Area above
22.66%
of scores are higher
How this works
A Z-score tells you how many standard deviations a raw score is from the mean. Positive means above average, negative means below average, and zero means exactly average. Use the percentile rank to see where the score sits in a normal distribution.
Formula
Z = (X − μ) ÷ σ
Example
Score 82 with class mean 75 and standard deviation 8 → Z = (82 − 75) ÷ 8 = 0.875 (≈ 81st percentile)