Free t Test CalculatorUnpaired, paired and Welch t tests with confidence intervals.

Paste two columns of values to compare their means: P value, the difference with its 95% confidence interval, t, degrees of freedom and Cohen’s d.
Switch to paired, Welch or the nonparametric Mann–Whitney and Wilcoxon tests in one click.

P value and 95% CIPaired or unpairedNo upload

No sign-up No upload No watermark

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Calculations run in your browser. Your data is not uploaded; the project is saved in this browser only.

THREE SIMPLE STEPS

How to use the t Test Calculator

Enter two groups

Type or paste the values in two columns. For a paired test, keep each pair on the same row.

Choose the test

Unpaired, Welch (unequal SDs), paired, or their nonparametric versions.

Report it

Copy the result table, read the summary sentence and save the graph with its significance bracket.

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t Test Calculator FAQ

Paired or unpaired?

Paired when each value in one group has a partner in the other (same subject before and after, matched samples); unpaired when the groups are independent.

What is Welch’s t test?

A t test that does not assume the two groups have the same SD. It is a safe default when the SDs differ.

Can I use mean, SD and n instead of raw data?

Yes. Change the Column table format to “Mean, SD, N” or “Mean, SEM, N” and enter one row per group. Unpaired t tests and ANOVA work from these summaries.

Is my data uploaded?

No. The test runs in your browser.

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