What is the syntax for T.DIST in Excel?

The syntax for T.DIST is: =T.DIST(x, deg_freedom, cumulative)

What is T.DIST used for?

T.DIST calculates probabilities from the Student's t-distribution, used when sample sizes are small or population standard deviation is unknown. It's essential for t-tests, confidence intervals, and hypothesis testing with sample data.

When should I use t-distribution vs normal distribution?

Use t-distribution when: sample size is small (n<30 is common rule), population standard deviation is unknown (using sample stdev), or you want more conservative estimates. As sample size increases, t-distribution approaches normal distribution.

What are degrees of freedom in T.DIST?

Degrees of freedom (df) typically equals n-1 for one sample, or n1+n2-2 for two samples. Lower df means heavier tails (more uncertainty). As df increases, t-distribution becomes more like normal. For df>30, they're nearly identical.

Statistical

T.DIST Function in Excel

Q: What are degrees of freedom in T.DIST?

Degrees of freedom (df) typically equals n-1 for one sample, or n1+n2-2 for two samples. Lower df means heavier tails (more uncertainty). As df increases, t-distribution becomes more like normal. For df>30, they're nearly identical.

Returns the Student's t-distribution.

Syntax

=T.DIST(x, deg_freedom, cumulative)

Arguments

x (required): Value to evaluate
deg_freedom (required): Degrees of freedom
cumulative (required): TRUE for CDF, FALSE for PDF

Examples

=T.DIST(1.96, 30, TRUE) - t-distribution CDF - Result: 0.97

T.DIST for data analysis

Confirm whether you need entire columns, filtered subsets, or distinct values.
Use [COUNTIFS](/functions/countifs/) and [SUMIFS](/functions/sumifs/) for multi-criteria metrics.
Pivot tables complement single-cell statistical formulas for exploration.

Common errors

#NUM! if deg_freedom < 1

Use cases

Hypothesis testing
Confidence intervals
Small samples

Frequently asked questions

What is T.DIST used for? T.DIST calculates probabilities from the Student's t-distribution, used when sample sizes are small or population standard deviation is unknown. It's essential for t-tests, confidence intervals, and hypothesis testing with sample data.
When should I use t-distribution vs normal distribution? Use t-distribution when: sample size is small (n<30 is common rule), population standard deviation is unknown (using sample stdev), or you want more conservative estimates. As sample size increases, t-distribution approaches normal distribution.
What are degrees of freedom in T.DIST? Degrees of freedom (df) typically equals n-1 for one sample, or n1+n2-2 for two samples. Lower df means heavier tails (more uncertainty). As df increases, t-distribution becomes more like normal. For df>30, they're nearly identical.

Editorial review

Reviewed by Excel.Directory Editorial Team. Updated May 2026.