# Z Test Calculator

> Z test calculator: z-score for a sample mean vs a known population. Free z test calculator with the formula shown - runs entirely in your browser, no signup.

- **Canonical URL:** https://boringtoolskit.com/z-test-calculator/
- **Category:** Statistics
- **Evidence level:** catalogue
- **Reviewed:** July 26, 2026
- **Last verified:** 2026-10-12
- **Privacy:** Inputs and results stay in this browser unless the page clearly labels an external request.

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