P-Value Calculator

How to interpret a p-value

The p-value is the probability of observing a test statistic as extreme as (or more extreme than) the one computed, assuming the null hypothesis (H₀) is true. A p-value below your significance level α (commonly 0.05) means you reject H₀. The p-value is NOT the probability that H₀ is true — it is a measure of how surprising the data is under H₀. Multiple testing inflates false positives; apply Bonferroni correction when testing many hypotheses.