Aisha K.
Mar 12, 2026
Clean layout and the results update instantly. Exactly what I needed for a quick planning check.
Statistics, Probability & Advanced Math
How to Calculate Z-score and P-value
Instant math result
Z-scores show how many standard deviations a value sits from the mean. This calculator also approximates a two-tailed normal p-value for quick inference checks.
Inputs
-100010000
-100010000
0.011000
Smart analysis
Recommendations
Tailored to your live inputs and result—guidance only, not professional advice.
- Check units
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Most calculation mistakes come from mixed units or the wrong mode (degrees vs radians, hyp vs leg). Double-check labels before using the number.
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Plain-English guide
Terms & how it works
Confused by a field? Read the short definitions here while you use the tool.
Raw Score (x)
The “Raw Score (x)” value used in this tool’s formula. Adjust it to see results update live.
Mean (μ)
The “Mean (μ)” value used in this tool’s formula. Adjust it to see results update live.
Standard Deviation (σ)
The “Standard Deviation (σ)” value used in this tool’s formula. Adjust it to see results update live.
- x
Observation
Raw score.
- μ,σ
Mean & SD
Reference distribution.
When to use this Z-Score and P-Value
Common use cases
- Check homework results with transparent formulas
- Estimate probability for common distributions
- Convert between related statistical measures quickly
Localized examples
- Classroom and exam-prep workflows
- Business analytics back-of-envelope checks
What you get
- Formula-backed outputs with clear labels
- Step-friendly defaults for learning
- Free online calculator — no sign up
How to Calculate Z-Score and P-Value Step-by-Step
- 1Enter the raw score.
- 2Provide population/sample mean and SD.
- 3Review z-score and approximate p-value.
Governing formula
z = (x − μ) / σ
Standardizes a value and relates it to a normal-tail probability.
Example: set Raw Score (x) = 85, Mean (μ) = 70, Standard Deviation (σ) = 10, then read the result.
Variable definitions
- x
Observation
Raw score.
- μ,σ
Mean & SD
Reference distribution.
- p-values assume a normal model.
Frequently Asked Questions
It is a normal-approximation estimate suitable for learning and quick checks.
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Reviews & Ratings
See what others think about this tool, then leave your own rating to help improve CalculioHub.
4.8
out of 5.0
4 reviews
Daniel R.
Feb 28, 2026
Very usable on mobile. Would love a save/export option later, but the math feels solid.
Priya S.
Feb 3, 2026
The FAQ section answered my questions before I even had to search. Smooth dark mode too.
Marcus L.
Jan 19, 2026
Simple inputs, clear outputs. This replaced three bookmarks I used to juggle.
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