P-Value Calculator (Z-Test)
Use this p-value calculator (z-test) to estimate a p value for a z test. Enter test statistic, tail choice and significance settings and review the p value and related test result.
P-value
—
Significant at α=0.05? —
Significant at α=0.01? —
✉ Email me this result
</> Embed this calculator
Paste this into any website or blog post. It is free — the small "powered by" link must stay visible.
How it works
One-tailed p = 1 − Φ(|z|); two-tailed p = 2 × (1 − Φ(|z|))How to use the P-Value Calculator (Z-Test)
Start by entering test statistic, tail choice and significance settings. Keep the units consistent and check that each value belongs to the same question.
The result gives the p value and related test result. The conclusion depends on the hypothesis, assumptions and chosen significance level. Use it as a guide and check any instructions, rules or professional advice that apply.
Frequently Asked Questions
What does this p-value calculator (z-test) calculate?
It gives the p value and related test result. The conclusion depends on the hypothesis, assumptions and chosen significance level.
What information should I enter?
Enter test statistic, tail choice and significance settings. Use the same units throughout so the result is easier to understand.
Does a small p value prove the result is important?
No. It indicates how unusual the data are under the tested assumption, not practical importance.