P-Value Calculator
Calculate P-values and visualize statistical significance
Enter either the Z-Score or the Raw Score along with Mean and Standard Deviation.
Standard Normal Distribution (Bell Curve)
This graph shows where your Z-score falls on the standard normal distribution curve
How this P-Value Calculator Works
The P-Value Calculator follows these steps:
- Enter either a Z-score directly or provide raw score with population parameters
- Select the test type (one-tailed or two-tailed)
- Choose your desired decimal precision
- The calculator computes the p-value and provides detailed interpretation
Why Use This P-Value Calculator?
Accurate Results
Get precise p-values with customizable decimal precision.
Visual Representation
See the significance level on an interactive normal distribution graph.
Detailed Analysis
Receive comprehensive interpretation and calculation steps.
Frequently Asked Questions
What is a P-value?
A P-value is the probability of obtaining test results at least as extreme as the observed results, assuming the null hypothesis is true. It helps determine statistical significance.
What's the difference between one-tailed and two-tailed tests?
A one-tailed test looks for an effect in one direction only (greater than or less than), while a two-tailed test looks for an effect in both directions (different from). Two-tailed tests are more conservative.
How do I interpret the results?
Generally, a P-value less than 0.05 is considered statistically significant, suggesting strong evidence against the null hypothesis. The smaller the P-value, the stronger the evidence.