# 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:

Arguments

| Argument | Description |
| --- | --- |
| value | The value at which<br>you want to evaluate the distribution. The value<br>must not 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.

[](https://help.qlik.com/en-US/sense/Subsystems/Hub/Content/Sense_Hub/Scripting/StatisticalDistributionFunctions/TDist.htm)

#### 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/sense/May2026/Subsystems/Hub/Content/Sense_Hub/Scripting/StatisticalDistributionFunctions/TInv.htm)