# T-Test Calculator - T-Distribution Critical Values Table

T-test is a statistical test that is used to determine if there is a significant difference between the mean or average scores of two groups.

Is This Tool Helpful?

The t-test determines if the means are sufficiently different from each other to say that they belong to two distinct groups. It also takes into account the variability in scores of the two groups. A distribution or T-test used to test a hypothesis about a population mean when the population standard deviation is not known, the sample size is small, and the normal distribution is assumed for the sample mean. The T distribution is also known as the "Student's T Distribution".

A T distribution differs from the normal distribution by its degrees of freedom. A T-test is a statistical hypothesis test that follows a student’s distribution if the null hypothesis is supported. Calculate the T-Test Critical Value by using the t-distribution critical values table.
Example:
Calculate the T- Test Critical Value for the given details by using t-distribution critical values table.
Degrees of Freedom (df) = 25
Two tailed probability Value α = 0.01
One tailed probability Value α = 0.025

Solution:
Two-tailed T Value = 1.7081

One-tailed T Value = 2.0596