Stats Assistance A free project by ReliCheck

Run the test. Read the result.
Report it right.

Free statistical calculators built for students and researchers. Every result comes with a copy-ready APA 7 write-up, a plain-language interpretation, and nothing to install.

Browse calculators Help me choose a test
Calculators

Pick your analysis

Independent samples t test Compare the means of two separate groups. Student and Welch versions, from raw data or summary statistics. t(df) = ?, p, d, 95% CI Paired samples t test Compare two measurements from the same people, such as pre and post scores. t(df) = ?, p, d, 95% CI One sample t test Test whether a group mean differs from a known or hypothesized value. t(df) = ?, p, d, 95% CI Chi-square test Test of independence for contingency tables, plus goodness of fit for a single variable. χ²(df) = ?, p, V Correlation Pearson and Spearman correlation between two variables, with significance test. r = ?, p, 95% CI Effect size (Cohen's d) Compute d from means and SDs or from a t statistic, with pooled and Hedges' g options. d, g, r, benchmarks Confidence intervals Confidence interval for a mean or a proportion at any confidence level. 95% CI [?, ?] Sample size How many participants you need for a t test or proportion comparison at a given power. n per group at 80% power Text analyzer Paste open-ended responses or interview text, get word frequencies, phrases, and candidate themes. words, phrases, themes Descriptive statistics Paste data, get mean, SD, median, quartiles, skewness, and kurtosis in one pass. M, SD, Mdn, IQR, skew
Not sure where to start?

Answer four questions, get the right test

Choosing the wrong test is the most common statistics mistake in student research. Our interactive guide walks through your research question, your variables, and your design, then points you to the correct analysis and the calculator to run it.

Which statistical test should I use?
When a calculator is not enough

Ask a human statistician

Some questions need judgment, not a formula: whether your analysis plan will survive the committee, whether the model fits the design, whether the results section says what the numbers actually say. Our consulting service puts a human PhD statistician on your project, with a written review at a fixed price.

Statistical consulting Services and prices
Why these calculators

Built the way results should be reported

Most free calculators stop at a p value. Ours report the full picture: the test statistic, degrees of freedom, exact p value, effect size, and confidence interval, assembled into an APA 7 formatted sentence you can copy straight into your paper.

Stats Assistance is a free project by ReliCheck, the research ecosystem behind Quanta, a native Mac statistics app. When your analysis outgrows a web calculator, with real datasets, assumption checks, charts, and full APA tables, Quanta picks up where these pages leave off.

ReliCheck Quanta for Mac. The full version of everything here: a complete analysis suite, assumption checks, publication-ready APA tables, and speed that beats R and Python on common workflows. Free to try.

Learn about Quanta