Question
What does a z-score mean?
A z-score shows how many standard deviations a value is above or below the mean.
Math
Use OmniCalc's z-score calculator to see how far a value is from the mean in standard-deviation units.
Z-score calculator
Enter a value, mean, and standard deviation to calculate the z-score and a quick percentile estimate.
Why this result matters
A clean approved-list stats page that extends the standard-deviation cluster into standardized-score analysis. Use the tool above to enter a few clear inputs and get a practical answer you can use right away.
This z-score calculator helps students and analysts standardize a value against a mean and standard deviation. It shows the z-score, distance from the mean, and an approximate percentile estimate for quick interpretation.
Formula and method
The calculator subtracts the mean from the value and divides the result by the standard deviation to compute the z-score, then estimates the percentile assuming a normal distribution.
Example
If a score is 82, the mean is 70, and the standard deviation is 10, the z-score is 1.2.
FAQ
Short answers to the questions people often ask before or after using the tool.
Question
A z-score shows how many standard deviations a value is above or below the mean.
Question
It means the value is below the mean.
Question
The standard deviation must be greater than zero to calculate a valid z-score.
Next stats calculator
These follow-up calculators help users move from summary stats into spread, probability, and score interpretation without leaving the cluster.
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Use OmniCalc's standard deviation calculator to measure how spread out a list of numbers is with either sample or population mode.
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Use OmniCalc's mean, median, mode, range calculator to summarize a list of numbers and understand the center and spread of your data quickly.
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Use OmniCalc's confidence interval calculator to estimate a plausible range around a sample mean using a chosen confidence level.
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Use OmniCalc's probability calculator to find the chance of an event from favorable and total outcomes.