P value from a test statistic

Enter the statistic you already calculated. Chi-square is reported as an upper-tail p value, which is the usual test.

Two-sided p
0.0500
One-sided p
0.0250

Questions

What does this p-value calculator do?

It turns a z score, a t statistic with degrees of freedom, or a chi-square statistic into a one-sided and a two-sided p value. It does not run the test from raw rows.

Should I use a one-sided or two-sided p value?

Use the sidedness written in the analysis plan. A two-sided p value is the usual default when a difference in either direction would count.

Is a p value below 0.05 a real finding?

No. 0.05 is a convention, not proof. A study still needs the pre-specified test, the sample, and a look at the effect size.

Educational only. Not medical advice, not a regulatory determination, and not a substitute for qualified RA/QA, legal, clinical, or statistical counsel. P value calculator does not submit to FDA, Notified Bodies, or IRBs.