Zスコア計算機

共有リンク

はじめに

Z-Score Calculator — Standardize a value and get its percentile. Enter Value (x), Mean (μ), Std. deviation (σ) to get an instant, accurate result.

計算式

z = (x − mean) / standard deviation. Percentile derived from the standard normal cumulative distribution function.

ステップごとの説明

Enter the Value (x).
Enter the Mean (μ).
Enter the Std. deviation (σ).
Click Calculate to see your result instantly.

実例

Example: With Value (x) = 85, Mean (μ) = 75, Std. deviation (σ) = 10, the Z-Score Calculator gives Z: 1, Percentile: 84.1345.

よくある質問

What does a z-score of 0 mean?

The value is exactly equal to the mean.

What does the percentile tell me?

The percentage of the distribution that falls below your value, assuming a normal distribution.

What inputs does the Z-Score Calculator need?

You'll need to provide: Value (x), Mean (μ), Std. deviation (σ). All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.

How accurate is the Z-Score Calculator?

The Z-Score Calculator applies the formula exactly as calculated — z = (x − mean) / standard deviation. Percentile derived from the standard normal cumulative distribution function. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.

Is the Z-Score Calculator free to use?

Yes, the Z-Score Calculator is completely free, requires no signup, and runs instantly in your browser.