How to calculate t value in Excel

In this Excel tutorial lesson, we will learn a very useful financial term known as T-Value.

Understanding T-Value

A T-Value is a statistical calculation using the mean, standard deviation, and degrees of freedom. It will help in financial projections and forecasting.

With this information, a business owner can calculate the statistical low and high for earnings in a specific month and with a degree of confidence that the future earnings will fall within that range, which helps with better business planning. Projections might suggest that the business can expect to gross $150,000 in May and the T-Value might tell them that number has a 90-percent rate of confidence. If the confidence rate is less than 50-percent, the business can plan for the potential of a lower return and work to increase the T-Value for future months and years.

The syntax

Let us show you how to calculate the T value using a simple formula in Excel:

The Formula =T.DIST(x,deg_freedom,tails)

The T.DIST function uses the following arguments:

  • X (required argument) – This is the numeric value at which we wish to evaluate the T Distribution.
  • Deg_freedom (required argument) – An integer that indicates the number of degrees of freedom.
  • Tails (required argument) – This specifies the number of distribution tails that would be returned. If tails =1, T.DIST returns the one-tailed distribution. If tails = 2, T.DIST returns the two-tailed distribution.


Let’s create the data for the calculation:

T dist function

  • x: 2
  • degrees of freedom: 10
  • Tails: 1

The T.DIST formula

The formula is applied as below:

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excel t.dist function

Result is:

excel t.dist formula

The Tdist function result is 0.963306

The T.INV formula

To calculate the t-value in Microsoft Excel, you can also use the “T.INV” function. The T.INV function calculates the one-tailed probability of the t-distribution. The function has two arguments:

  1. Probability (p): The probability associated with the t-distribution. This argument must be between 0 and 1, exclusive.
  2. Degrees of freedom (df): The number of degrees of freedom in the t-distribution. This argument must be greater than 0.


To calculate the t-value with a probability of 0.025 and degrees of freedom of 10, you would enter the following formula in a cell in Excel:

=T.INV(0.025, 10)

This formula returns the critical T-value for a one-tailed distribution with a 2.5% significance level and 10 degrees of freedom.

This would return the t-value of -1.83311293.