Using the P-value Calculator
Select the tail that matches the hypothesis specified for the analysis. An upper-tail test asks about unusually high values, a lower-tail test about unusually low values, and a two-sided test considers either direction.
Worked example
Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.
Example inputs
- Z statistic
- 1.96
- Alternative
- Two-sided
Example result
- P-value
- 0.049995652
Method and assumptions
Normal z-test approximation using the error function. Does not evaluate t, F or chi-square statistics.
Check what the data represents
A statistical result is only meaningful in relation to the observations and assumptions behind it. Keep track of whether values describe a whole population or a sample, whether observations are independent, and which distribution the method uses. More decimal places cannot compensate for a sample that does not represent the question you are trying to answer.
Common question
Can I enter a t statistic instead of a z statistic?
No. A t statistic uses a t distribution and degrees of freedom. This calculator uses the standard normal distribution only.
Guide updated .