Many students struggle to find critical values of z, t, and Chi-square for hypothesis tests. No matter how often I show them how to use the StatCrunch calculators to do this, they gravitate back to the tables. And make a lot of mistakes. To help a bit, I have created some Excel calculators that should make it a bit easier. A minimum of data/info is needed to use the calculators. First, you need to know which distribution you need and I have covered this in other posts. For the z, you just need to know alpha and the tail of the test which is always indicated by the math operator in the alternative hypothesis. For the t, things get a bit more complicated as you also need to know the sample size(s) and whether or not the variances are assumed to be equal if you are dealing with a two-sample test. Note you can use these calculators to find the degrees of freedom for the different tests too.
I have embedded the Critical Values workbook below. In each, you enter your data in the blue cells and all answers show up in yellow cells. In some, you will need to select options in an orange cell. As an example of how they work, here is how to use the Two Independent Samples Critical Values calculator:
This is the index of calculators.