The Excel TINV function returns the two–tailed inverse of the Student's t–distribution. It is a legacy name — Microsoft now recommends T.INV.2T, which is identical.
Syntax
| Argument | Description | |
|---|---|---|
probability | Required | The two–tailed probability (between 0 and 1). |
deg_freedom | Required | The degrees of freedom (a positive integer). |
How to use it
TINV is the inverse of the two-tailed t–distribution: give it a probability and it returns the t–value whose two-tailed area equals that probability.
This is the value you compare against in a two-tailed t–test at the 5% level with 10 degrees of freedom. Because it is two-tailed, TINV(0.05, df) equals the one-tailed t at the 0.025 level.
Use the modern name: =T.INV.2T(probability, df) is the direct replacement and returns the same value. For a one-tailed (left) inverse use T.INV.
Try it: interactive demo
Pick a TINV example to see the formula and its result.
Practice workbook
Frequently asked questions
Is TINV the same as T.INV.2T?
T.INV.2T (Excel 2010+) is the two-tailed inverse and returns identical results. The newer one-tailed inverse is T.INV.Is TINV one-tailed or two-tailed?
TINV(0.05, df) matches the one-tailed t at the 0.025 level.How does TINV relate to TDIST?
TDIST turns a t–value into a probability, and TINV turns a two-tailed probability back into a t–value.Should I switch to T.INV.2T?
.2T suffix makes the two-tailed behaviour explicit. Existing TINV formulas keep working.Master functions like this in one day
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