Bonferroni Correction Calculator
Adjust a significance threshold and one p-value for a family of multiple tests. Enter probabilities from 0 to 1.
Formula
Per-test threshold = α/m; adjusted p = min(1, mp).
Per-test threshold ≈ (0.05)÷(10) · Adjusted p-value ≈ min(1,(0.003)×(10))
How to use
- Enter the family significance level α.
- Enter all m tests in the family and one raw p-value.
- Compare raw p with α/m, or adjusted p with α.
Examples
- α = 0.05, m = 10, p = 0.003 give threshold 0.005 and adjusted p = 0.03.
Frequently asked questions
Must tests be independent?
No. The union bound controls familywise error even with dependent tests.
Why cap adjusted p at 1?
An adjusted p-value cannot exceed 1.
Which tests count?
Include the entire planned family, not only significant results.
Sources
Updated: