## What Is TDIST Function In Excel?

The

TDISTfunction in Excel determines the Student’s t-distribution probability percentage. Users can apply this function while performing hypothesis testing of small sample datasets.

However, the **TDIST **Excel function got replaced in Excel 2010 with newer functions, such as **T.DIST.RT** and **T.DIST.2T**, with improved accuracy. So, it is now available as a **Compatibility** function for backward compatibility.

For example, the first table shows the input values required to calculate the Student’s t-distribution probability percentage.

Suppose the requirement is to determine the one- and two-tailed t-distribution probability percentages for the given input value sets and display the output in cell range D8:D9. And the target cell range D8:D9 have the **Number Format** set as **Percentage** in the **Home** tab.

Then applying the **TDIST **Excel function in the target cells will get us the required probability values.

In this **TDIST **Excel function example, the cell D8 formula accepts the argument values in **Value Set 1**. And as the third argument value is **1**, the function returns the one-tailed t-distribution probability percentage, **2.55%**.

Similarly, the cell D9 formula accepts the argument values in **Value Set 2**. And as the third argument value is **2**, the function returns the two-tailed t-distribution probability percentage, **5.09%**.

##### Table of contents

###### Key Takeaways

- The
**TDIST Excel function**computes the t-distribution probability of an event across a sample data set. The function is useful for performing hypothesis testing of small sample sets. - The
**TDIST**function is a**Compatibility**Excel function, as it got replaced by newer functions, such as**T.DIST.RT**and**T.DIST.2T**, with improved accuracy. - As input, the
**TDIST**function accepts three mandatory arguments,**x**,**deg_freedom**, and**tails**. - If
**x**is negative, the formula you must apply to get the one-tailed t-distribution probability is**1 – TDIST(x,deg_freedom,1)**. And to calculate the two-tailed t-distribution probability, use the formula**TDIST(x,deg_freedom,2)**.

### TDIST() Excel Formula

The **TDIST **Excel function syntax is:

where,

**x**: A computed numeric value of t with which we calculate the Student’s t-distribution.**deg_freedom**: An integer value denoting the number of degrees of freedom.**tails**: The number of distribution tails you require the**TDIST**Excel function to return. This argument can take the value**1**or**2**, indicating one- or two-tailed t-distribution.

All three arguments in the above **TDIST **Excel function syntax are mandatory.

Further, below are the critical aspects of the **TDIST()** you must know before applying the function.

- The
**deg_freedom**and**tails**argument values get truncated to integer values. - If the
**tails**argument value is**1**, the**TDIST**Excel function output will be**P**, with**X**, a random variable following the t-distribution, greater than**x**. And if the**tails**argument value is**2**, the**TDIST()**output will be**P**, with**X**greater than**x**or less than**-x**. - If
**x**is less than**0**, the**TDIST(-x,deg_freedom,1)**is equal to the formula**1 – TDIST(x,deg_freedom,1)**and results in**P**, with**X**greater than**-x**. And the**TDIST(-x,deg_freedom,2)**is equal to**TDIST(x,deg_freedom,2)**and results in**P**, with the absolute value of**X**greater than**x**. - If we supply a non-numeric argument value, the
**TDIST**Excel function throws the**#VALUE!**error. - Suppose the
**x**value is less than**0**, the**deg_freedom**value is less than**1**, or the**tails**argument value is not**1**or**2**. Then, the**TDIST()**output is the**#NUM!**error.

### How To Use TDIST Excel Function?

The steps to apply the **TDIST **Excelfunction are as follows:

- First, ensure the source data contains the required numeric values and is valid.
- Then, select the required target cell, and enter the
**TDIST**Excel function. - Finally, press
**Enter**to view the t-distribution probability percentage.

The below example explains the above steps to apply the **TDIST **Excel function.

The following table contains the values required to calculate the one-tailed t-distribution probability percentage.

And suppose the requirement is to determine and display the one-tailed t-distribution probability percentage in cell B8, assuming the cell’s data format is **Percentage**. Then, you can use the **TDIST **Excel function in the target cell and achieve the required probability value.

**Select the target cell B8, enter the following TDIST(), and press Enter.***=TDIST(C3,C4,C5)*

You can also enter the argument values directly as numeric values, as shown below.

Once you enter the first two argument values and a comma, Excel will show the drop-down list to select the**tails**argument value.

The requirement is to calculate one-tailed distribution. So, double-click on the first option and close the parenthesis.

And once we press**Enter**, the function gets executed.

Alternatively, we can enter the**TDIST**Excel function using the option in the**Formulas**tab. And for that, we must select the target cell B8 and click**Formulas**→**More Functions**→**Compatibility**→**TDIST**to open the**Function Arguments**window.

In the**Function Arguments**window, we can enter the cell references to the respective argument values or the numbers directly in the corresponding fields.

And once we click**OK**in the**Function Arguments**window, the**TDIST**Excel function will get executed in the target cell B8.

In this example, the one-tailed t-distribution probability for exact**1**and the given degree of freedom,**20**, is**16.46%**. The**TDIST**Excel function returns a decimal value. But, as the**Number Format**of the target cell is**Percentage**, we get the result as a percentage value.

### Examples

Check out the below **TDIST **Excel function examples to learn about the function effectively.

#### Example #1

We can apply the **TDIST **Excel function to determine the p-value in a T-Test to confirm whether to reject or go with the null hypothesis.

Consider the following table containing T-Test data.

Suppose we must determine the p-value in cell B7, based on the given date, to compare it with **Alpha** and decide on the null hypothesis. Then, we can apply the **TDIST **Excel function in the target cell and get the required p-value.

**Step 1:**Select the target cell B7, enter the following**TDIST**Excel function, and press**Enter**.

*=TDIST(B5,B3-1,1)*

The function considers the upper end of the T-Test curve, as **x **can only be a positive value. And hence, we shall consider this case as one-tailed.

The **TDIST()** accepts the calculated** t-statistic** value as **x**. The **deg_freedom** value is one less than the given sample size, so the second argument takes the value **9**. And the function sets the **tails** argument value as **1** to return the **p-value** as a decimal, **0.004615**.

So, as the **p-value** is less than the **Alpha**, you should reject the null hypothesis.

#### Example #2

This example shows how to use the **TDIST Excel function** when **x** is negative.

The table below contains two sets of **TDIST **Excel function argument values, with the **x** value being negative in both scenarios.

Suppose the requirement is to calculate and display the one- and two-tailed t-distribution probability percentages in cell range D8:D9 for the two given value sets. And assume the target cells data format is **Percentage**.

Then applying the **TDIST **Excel function in the target cells in the below ways can fetch you the required data.

**Step 1:**Select the target cell D8, enter the below formula, and press**Enter**.

*=1-TDIST(2,60,1)*

As **x** is negative, we need to apply the **TDIST **Excel function, as explained above, to obtain the one-tailed t-distribution probability percentage.

**Step 2:**Select the target cell D9, enter the below formula, and press**Enter**.

*=TDIST(2,60,2)*

As **x** is negative, we need to apply the **TDIST **Excel function in the above manner when the **tails **argument value is **2**.

#### Example #3

We shall now see how to apply the newer Excel functions, such as **T.DIST**, **T.DIST.RT**, and **T.DIST.2T**, which replaced the **TDIST **Excel function.

We can either directly enter them in the required cell or access them by clicking **Formulas** → **More Functions** → **Statistical**. And they work with improved accuracy, with their names better indicating their purpose.

The first table shows the data required to supply as input to the **TDIST** and the latest functions.

Suppose the second table contains the different T-Test types, and the requirement is to determine the p-value in each case and display the output in cell range C9:C14.

Then, here is how we can apply the functions mentioned in the range B9:B14 in the target cells and achieve the required p-value for each T-Test type.

**Step 1:**Select the target cell range C9:C14 and set the**Number Format**in the**Home**tab as**Percentage**to view the p-values as percentages.

**Step 2:**Select the target cell C9, enter the**TDIST()**, and press**Enter**.

*=TDIST(C3,C4,1)*

As the T-Test type is one-tailed, the **tails **argument value is **1**. So, the one-tailed t-distribution probability for exact **0.8 **and the given degree of freedom, **5**, is **23%**.

**Step 3:**Select the target cell C10, enter the**TDIST()**, and press**Enter**.

*=TDIST(C3,C4,2)*

As the T-Test type is two-tailed, the **tails **argument value is **2**. So, the two-tailed t-distribution probability for exact **0.8 **and the given degree of freedom, **5**, is **46%**.

**Step 4:**Select the target cell C11, enter the**T.DIST.RT()**, and press**Enter**.

*=T.DIST.RT(C3,C4)*

As the T-Test type is right-tailed, we apply the function** T.DIST.RT** for better accuracy. And it accepts two argument values as input. So, the right-tailed t-distribution probability for exact **0.8 **and the given degree of freedom, **5**, is **23%**.

**Step 5:**Select the target cell C12, enter the**T.DIST.2T()**, and press**Enter**.

*=T.DIST.2T(C3,C4)*

As the T-Test type is two-tailed, we apply the **T.DIST.2T()** for better accuracy. And it accepts two argument values as input. So, the two-tailed t-distribution probability for exact **0.8 **and the given degree of freedom, **5**, is **46%**.

**Step 6:**Select the target cell C13, enter the**T.DIST()**, and press**Enter**.

*=T.DIST(C3,C4,TRUE)*

As the T-Test type is left-tailed and cumulative distribution, we apply the **T.DIST()**. It accepts the two given values as the first and second arguments and takes the third argument value as **TRUE**. So, the required t-distribution probability for exact **0.8 **and the given degree of freedom, **5**, is **77%**.

**Step 7:**Select the target cell C14, enter the**T.DIST()**, and press**Enter**.

*=T.DIST(C3,C4,FALSE)*

As the T-Test type is left-tailed and has probability density, we apply the **T.DIST()**. It accepts the two given values as the first and second arguments and takes the third argument value as **FALSE**. So, the required t-distribution probability for exact **0.8 **and the given degree of freedom, **5**, is **26.45%**.

### Important Things To Note

- The
**TDIST**Excel function syntax is =TDIST(x,deg_freedom,tails). - x denotes the computed numeric value of t with which we calculate the Student’s t-distribution.
**deg_freedom**is the integer value denoting the number of degrees of freedom.**Tails**shows the number of distribution tails we require the**TDIST**Excel function to return. It can take the value**1**or**2**.- The
**deg_freedom**and**tails**get truncated to integers. - For non-numeric argument values, the
**TDIST**Excel function output will be the**#VALUE!**error. - For
**x**less than**0**,**deg_freedom**less than**1**, or**tails**not being**1**or**2**, the**TDIST()**throws the**#NUM!**error.

### Frequently Asked Questions (FAQs)

**1. How can you apply the TDIST function in Excel VBA?**

You can apply the **TDIST **function in Excel VBA using the method:**Application.WorksheetFunction.TDist(Arg1,Arg2,Arg3)**

Arguments **Arg1**, **Arg2**, and **Arg3** correspond to the **TDIST()** arguments, **x**, **deg_freedom**, and **tails**.

Using an example, let us see how to apply the above method in Excel VBA.

The table below contains the **TDIST()** argument values.

And suppose the requirement is to calculate and show the two-tailed t-distribution probability percentage in cell D8 based on the given input data. Then, here is how you can apply the **TDIST** function in Excel VBA to display the result in the target cell.**• Step 1: **Using the keys **Alt **+ **F11**, open the VBA Editor.**• Step 2: **Choose the required **VBAProject** and go to **Insert** → **Module** to open a new module window, **Module1**.**• Step 3: **Enter the code in the **Module1** window to apply the **TDIST** function in Excel.**Sub TDIST_fn()**

Range(“D8”) = Application.worksheetFunction.TDist(Range(“C3”), Range(“C4”), Range(“C5”))**End Sub****• Step 4: **Click the **Run Sub/UserForm** button to run the **Module1** code.

And once the code executes, you can view the **TDIST()** output in the target cell D8.**• Step 5: **Select cell D8 and set the **Number Format** in the **Home** tab as **Percentage**.

The method in the provided code accepts the given input values as the argument values to return the required two-tailed t-distribution probability, **0.6666667**.

**2. What is the use of the TDIST Excel function?**

The use of the **TDIST **Excel function is that it helps in hypothesis testing of small sample sets.

**3. Why is the TDIST function in Excel not working?**

The **TDIST **function in Excel is not working, perhaps because of the following reasons:**• **You supplied non-numeric argument values to the **TDIST()**.**• **The provided **x **value is less than **0**.**• **The supplied **deg_freedom** argument value is less than **1**.**• **The specified **tails** argument value is not **1 **or **2**.

### Download Template

This article must be helpful to understand the **TDIST Excel**, with its formula and examples. You can download the template here to use it instantly.

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This has been a guide to TDIST Excel. Here we learn how to use the TDIST() function formula with step-by-step examples & downloadable excel template. You can learn more from the following articles –

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