P-value in Excel
Use Excel T.TEST for a two-tailed unequal-variance t-test and compare a worked example to the canonical A/B test logic.
At a glance
- Answer
- T.TEST(array1, array2, 2, 3) returns a two-tailed p-value for unequal variances.
- Because
- Tails 2 is two-tailed; type 3 is Welch, which does not pool the variances.
- Common error
- Type 2 can miscalibrate the standard error and Type I error when variances differ.
- Not for
- Running the test itself, or getting a confidence interval. t-Test Calculator
Excel p-value
Paste formula
=T.TEST(A2:A10,B2:B10,2,3)
Probability density; Welch t distribution (55.334 df)
| Metric | Value |
|---|
Excel T.TEST(array1,array2,2,3) maps to a two-tailed Welch t-test
How?
How this is calculated
Microsoft documents `T.TEST` with `tails` and `type` arguments. This page uses tails `2` for a two-tailed p-value and type `3` for unequal variance. The optional summary-stat check calls the existing A/B test logic, which uses Welch's t-test for means.
Formula: Excel T.TEST(array1,array2,2,3) maps to a two-tailed Welch t-test
Sources
- Microsoft Support, T.TEST function. Microsoft. Retrieved .
- OpenStax Introductory Statistics, Two Population Means. OpenStax. Retrieved .
Method last reviewed