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T.DIST.RT Function

Excel 2010+

Summary

The T.DIST.RT function calculates the right-tailed probability of the Student's t-distribution, essential for statistical hypothesis testing with small sample sizes. It replaces traditional t-distribution tables by providing precise probability values directly within Excel.

Syntax

T.DIST.RT(x, deg_freedom)

Parameters

Parameter	Type	Required	Description
x	`Number`	Yes	The numeric t-statistic value to evaluate
deg_freedom	`Integer`	Yes	Number of degrees of freedom (integer ≥ 1)

Using the T.DIST.RT Function

T.DIST.RT is primarily used in statistical analysis for determining p-values in one-tailed t-tests. Enter the calculated t-statistic and degrees of freedom to get the exact right-tail probability, making it invaluable for hypothesis testing, confidence intervals, and statistical decision-making.

Common T.DIST.RT Examples

Basic Right-Tail Probability

=T.DIST.RT(1.96, 60)

Calculates right-tailed probability for t=1.96 with 60 degrees of freedom (result: approximately 0.0273 or 2.73%)

Hypothesis Testing p-value

=T.DIST.RT(2.5, 30)

Returns p-value for one-tailed test with t-statistic 2.5 and 30 degrees of freedom

Quality Control Analysis

=T.DIST.RT(ABS(AVERAGE(B2:B11)-C1)/STDEV(B2:B11)/SQRT(10), 9)

Calculates one-tailed p-value for sample mean comparison (10 samples, 9 df)

Frequently Asked Questions

Right-tailed returns the probability in the upper tail (P(T > x)), used for upper one-tailed tests.

Use T.DIST.RT for one-tailed (upper) tests; T.DIST.2T for two-tailed tests.

Yes, as degrees of freedom increase, it approaches the normal distribution (use NORM.S.DIST for very large df).

Common Errors and Solutions

#VALUE!

Cause: Non-numeric input for x or deg_freedom

Solution: Ensure both arguments are valid numbers

#NUM!

Cause: Degrees of freedom less than 1

Solution: Use deg_freedom ≥ 1

Unexpected large values

Cause: x too extreme for given degrees of freedom

Solution: Verify t-statistic calculation and sample size

Notes

Available in Excel 2010 and later versions
If deg_freedom ≥ 100, results approximate NORM.S.DIST(x,TRUE)
For left-tail probabilities, use T.DIST(x,deg_freedom,TRUE)
Combines well with T.INV.RT for critical value calculations

Compatibility

Available in: Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365

Not available in: Excel 2007 and earlier

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2010+