Z-Score Calculator
Convert between z and probability and compute areas under the normal curve
Z-Score Calculator
Use this calculator to compute z-scores, convert between z and probability, and find the probability between two z-scores in a standard normal distribution.
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š§® Z-score z = (x ā Ī¼) / Ļ
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Steps
š Z-score and Probability Converter
Provide any one value to convert between z-score and probability P(X < Z), P(X > Z), P(0 to Z), P(-Z < X < Z), and P(X < -Z or X > Z).
Results
š Probability between Two Z-scores
Use this calculator to find the probability between two z-scores.
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What is z-score?
The z-score, also referred to as standard score, z-value, and normal score, indicates how many standard deviations a value is from the mean. Values above the mean have positive z-scores; values below have negative z-scores.
The z-score is calculated as:
where x is the raw score, Ī¼ is the population mean, and Ļ is the population standard deviation.
Z-table (0 to Z)
The values in the table represent the area between z = 0 and the given z-score.
| z | 0 | 0.01 | 0.02 | 0.03 | 0.04 | 0.05 | 0.06 | 0.07 | 0.08 | 0.09 |
|---|
How to read the z-table
- Column headings are the hundredth's place of the z-score.
- Row headings are the tenth's place of the z-score.
- Each value is the probability between 0 and Z under the standard normal curve.