p value calculator

P value calculator

Calculate the p-value for the following distributions:
Normal distribution, T distribution, Chi-Square distribution and F distribution.

Example digits=2: (0.001234 => 0.0012)
Left tail - the rejection area is a smaller value. right tail - the rejection area a greater value. two-tailed - the rejection area is split to both a smaller value or a greater value.
The test's statistic value
Standard deviation


P-value is the probability to get the current statistic result under the assumption that H0 is correct.
If you decide to reject the H0, P-value is the probability of type I error - rejecting a correct H0. A commonly used rule defines a significant level of 0.05. When the p-value is smaller than the significance level, you can reject the null hypothesis with a little chance of error. Another commonly used significant level is 0.01.

If you know the statistic value, choose the relevant distribution otherwise use one for the above test buttons.

p-value video