Z-Score Standardization Calculator

Summary

Paste a list of numbers, compute their z-scores using sample mean and standard deviation, and download a CSV of the results.

How it works

1. Paste or type your numbers into the input box, separated by commas, spaces, or newlines.
2. The tool computes the sample mean and sample standard deviation of your dataset.
3. Each value's z-score is calculated as (x − mean) / SD.
4. A table shows each original value alongside its z-score, rounded to 4 decimal places.
5. Click "Download CSV" to save the full results table to your computer.

Use cases

• Standardize features before running a machine learning algorithm.
• Identify outliers: values with |z| > 2 or 3 are typically flagged.
• Compare measurements from different instruments or scales.
• Prepare data for PCA or other methods that assume zero-mean input.
• Grade normalization across multiple exam versions.
• Remove scale effects when combining variables in a composite index.

Frequently Asked Questions