How it works
z counts standard deviations from the mean. Normal areas use Φ(z); any one area determines the rest.
z=(x−μ)/σ · P=Φ(z2)−Φ(z1) · 0→z=|Φ(z)−½|
When to use
Use this tool when you need to: try IQ: x=115, μ=100, σ=15 → z=1. Convert z=1.96 (≈95% central band). Area between −1 and 1 ≈68%.
How to use this tool
- Enter your values in the fields above.
- Review the formula and any mode options for your problem.
- Read the result and the step-by-step solution.
Try IQ: x=115, μ=100, σ=15 → z=1. Convert z=1.96 (≈95% central band). Area between −1 and 1 ≈68%.
Frequently asked questions
- What is the Z-score Calculator?
- z counts standard deviations from the mean. Normal areas use Φ(z); any one area determines the rest.
- How do I use the Z-score Calculator?
- Enter the required values, then calculate. The Z-score Calculator shows results, formulas, and step-by-step work when available. No account is required.
- What formula does the Z-score Calculator use?
- z=(x−μ)/σ · P=Φ(z2)−Φ(z1) · 0→z=|Φ(z)−½|
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