How to use the statistical tables generator
- Choose the table: standard normal, t critical values or chi-square critical values.
- Choose the decimal places, 3 or 4.
- For the standard normal table, enter the first z value, the last z value and the step.
- Copy, print or export the table to a spreadsheet as CSV.
Formula
Standard normal table: P(Z <= z) is the cumulative probability and P(Z > z) is one minus it
t table: for each degrees of freedom, the value with 0.1, 0.05, 0.025, 0.01 or 0.005 of the distribution above it
Chi-square table: the same upper tail areas, for each degrees of freedom
Every entry is computed from the exact distribution function and rounded to the places chosen
Entries are computed when you ask for the table, not copied from a printed source, so you can change the range and the step and get matching values.
A short z table and the critical values
The standard normal table from 0 to 3 in steps of 0.25 has 13 rows. The first row reads z = 0.00 with a cumulative probability of 0.5000 and an upper tail of 0.5000.
The t table lists, for 1 degree of freedom, 3.0777, 6.3138, 12.7062, 31.8205 and 63.6567 for upper tails of 0.1, 0.05, 0.025, 0.01 and 0.005. For 5 degrees of freedom the 0.025 value is 2.5706. The chi-square table for 1 degree of freedom reads 2.7055, 3.8415, 5.0239, 6.6349 and 7.8794 across the same tails.
Using a table
To read a one sided critical value from the t or chi-square table, choose the column for your upper tail area and the row for your degrees of freedom. For a two sided t test, use half of your significance level as the upper tail. A 5 percent two sided test uses the 0.025 column.
If you need a value that is not in the table, such as a probability of 0.9 or a degrees of freedom of 37, use the t, chi-square and F calculator.
From a score to a probability
The standard normal table turns a z score into the share of a normal distribution below it. First standardize your value with the z score calculator, then read the table. For a direct p value from a test statistic, the p value calculator does both steps.
Assumptions and limits
- The z range runs from -8 to 8, with a step you choose, and the table has at most 200 rows.
- The t and chi-square tables show upper tail areas and a fixed set of degrees of freedom.
- Values are rounded to the places you choose, so the last digit can differ from a source that rounds another way.
- Tables are for reference and study. Check the requirements of an exam or a journal before you rely on them.
Frequently asked questions
How do I read a z table?
Find your z value in the first column. The next column gives the share of the distribution below it, and the last gives the share above it.
Why are some t values the same as normal values?
As the degrees of freedom grow, the t distribution approaches the standard normal. The 0.025 value for large degrees of freedom is close to 1.96.
Can I change the step of the z table?
Yes. Enter any step, such as 0.01 for a fine table or 0.5 for a short one, up to 200 rows.
Can I print the table?
Yes. Use print for a clean page, or export CSV to open it in a spreadsheet.