Result
Enter values and select Calculate.
Formula and methodology
Z mode uses the standard normal CDF. T mode uses the Student t CDF with a positive integer degree of freedom. Two-tailed p = 2 × min(CDF, survival probability).
Worked example
For z = 1.96, the two-tailed p-value is approximately 0.0499957903.
Assumptions and interpretation
- Inputs and results remain in this browser and are not sent to analytics.
- This tool performs general educational statistical computation; it does not select a study design or validate scientific conclusions.
- Confidence-interval coverage describes repeated use of the method under its assumptions, not a probability assigned to the fixed parameter after calculation.
- Keep full precision for decisions; displayed values are rounded for readability.