To use this T critical value (t table) calculator, enter values in input box. The t table value calculator will instantly give you the t value for one tailed probability as well as two tailed probability. It can be significantly smaller, but you weren't asking that question. That would be a one-tailed test. For a two-tailed test if the calculated value of t exceeds the tabled value, then report the p value in the table. For a one-tailed test, the p value is divided by two. So 'p . 0.05' becomes 'p 0.025." The t-distribution table is a table that shows the critical values of the t distribution. To use the t-distribution table, you only need to know three values: The degrees of freedom of the t-test The number of tails of the t-test (one-tailed or two-tailed) The alpha level of the t-test (common choices are 0.01, 0.05, and 0.10) Critical Value Calculator. Use this calculator for critical values to easily convert a significance level to its corresponding Z value, T score, F-score, or Chi-square value. Outputs the critical region as well. The tool supports one-tailed and two-tailed significance tests / probability values. t Distribution: Critical Values of t Significance level Degrees of Two-tailed test: 10% 5% 2% 1% 0.2% 0.1% freedom One-tailed test: 5% 2.5% 1% 0.5% 0.1% 0.05% 1 6.314 12.706 31.821 63.657 318.309 636.619 2 2.920 4.303 6.965 9.925 22.327 31.599 3 2.353 3.182 4.541 5.841 10.215 12.924 4 2.132 2.776 3.747 4.604 7.173 8.610 MhSBph.

one tailed critical value table