How to Calculate P Value Calculator
What is P Value Calculator?
A p-value is the probability of obtaining a test result at least as extreme as the observed result, assuming the null hypothesis is true. A small p-value (typically < 0.05) suggests the result is unlikely due to chance alone.
Step-by-Step Guide
- 1State your null hypothesis (H₀) — usually "no effect" or "no difference"
- 2Calculate the test statistic (Z-score, t-score, etc.)
- 3Look up the p-value from the appropriate distribution
- 4If p < α (significance level), reject H₀
Worked Examples
Input
Z = 2.0, two-tailed
Result
p = 0.0455
Significant at α = 0.05 (p < 0.05)
Input
Z = 1.5, two-tailed
Result
p = 0.1336
Not significant at α = 0.05