# TDist - script and chart function

TDist() returns the probability for the Student's t-distribution where a numeric value is a calculated value of t for which the probability is to be computed.

Syntax:

TDist(value, degrees\_freedom, tails)

Return data type: number

Arguments:

TDIST arguments

| Argument | Description |
| --- | --- |
| value | The value at which you want to evaluate the distribution and must not<br>be negative. |
| degrees\_freedom | A positive integer stating the number of degrees of freedom. |
| tails | Must be either 1 (one-tailed<br>distribution) or 2 (two-tailed distribution). |

This function is related to the TInv function in the following way:   
`If prob = TDist(value, df ,2), 
 then TInv(prob, df) = value`

Limitations:

All arguments must be numeric, else NULL will be returned.

Examples and results:

Examples and results

| Example | Result |
| --- | --- |
| TDist(1, 30, 2) | Returns 0.3253 |

## Learn more

* [TInv - script and chart function](https://help.qlik.com/en-US/qlikview/September2026/Subsystems/Client/Content/QV_QlikView/Scripting/StatisticalDistributionFunctions/TInv.htm)