Significance Level Calculator: P-value vs. Alpha Decision Tool

Determine Your Hypothesis Test Decision

Enter the p-value obtained from your statistical test (between 0 and 1).
Enter your chosen significance level (commonly 0.05, 0.01, or 0.1).

Our Significance Level Calculator simplifies the crucial decision-making process in hypothesis testing. Easily compare your calculated p-value with your chosen alpha (α) level to determine if you should reject the null hypothesis or fail to reject it. This tool helps researchers, students, and analysts quickly interpret statistical significance for robust conclusions.

Formula:

The core principle for making a decision in hypothesis testing using the p-value and significance level (alpha) is:

  • If P-value ≤ α: Reject the Null Hypothesis (H0).
  • If P-value > α: Fail to Reject the Null Hypothesis (H0).

Where:

  • P-value: The probability of observing a test statistic as extreme as, or more extreme than, the one observed, assuming the null hypothesis is true. It quantifies the evidence against the null hypothesis.
  • α (Alpha): The chosen significance level, representing the maximum probability of making a Type I error (incorrectly rejecting a true null hypothesis). Common alpha levels include 0.05 (5%), 0.01 (1%), or 0.10 (10%).

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