How do I find the critical value of t in Excel?

You can use the T.INV() function to find the critical value of t for one-tailed tests in Excel, and you can use the T.INV.2T() function for two-tailed tests.

Example: Calculating the critical value of t in Excel
To calculate the critical value of t for a two-tailed test with df = 29 and α = .05, click any blank cell and type:

=T.INV.2T(0.05,29)