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F-Test Calculator

Three ways in: a one-way ANOVA from raw groups, a two-sample variance ratio, or a bare F with its two degrees of freedom. Each gives the p-value, the critical value at your α and the decision, from the same exact F distribution.

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F-Test Calculator works straight from this page — free, instant, nothing to install. It covers a one-way ANOVA from raw groups, a two-sample variance ratio, or a bare F with its two degrees of freedom. Each gives the p-value, the critical value at your α and the decision, from the same exact F distribution — adjust any of them and the result follows immediately.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What is F-Test Calculator?

Three ways in: a one-way ANOVA from raw groups, a two-sample variance ratio, or a bare F with its two degrees of freedom. Each gives the p-value, the critical value at your α and the decision, from the same exact F distribution.

What does it take into account?

It factors in a one-way ANOVA from raw groups, a two-sample variance ratio, or a bare F with its two degrees of freedom. Each gives the p-value, the critical value at your α and the decision, from the same exact F distribution. Change any of them and the output follows immediately.

When would I actually use this?

Summarising a dataset before drawing conclusions from it, checking whether a difference between two groups is real, and putting an interval around an estimate.

What is the most common mistake?

Reading a p-value as the probability that the hypothesis is wrong. It is the probability of seeing data at least this extreme if the null were true — a different statement, and a much weaker one.

How is F-Test Calculator different from Chi-Square Test Calculator?

They sit next to each other but answer different questions: Chi-Square Test Calculator is the one to open when you need it to χ² test of independence on any contingency table, showing observed, expected, the contribution and the standardised residual of every cell, plus Cramér's V. Cells with an expected count below 5 are flagged, because that is when the test stops being valid. Pick whichever matches what you're starting from — both are free.

Is there a tool for the next step?

Fisher's Exact Test Calculator is the closest one after this: The exact hypergeometric p for a 2×2 table — the right test when χ² fails on small counts. The two-tailed p sums every table at most as probable as the observed one, which is not the same as doubling the one-tailed p, and the odds ratio comes with its confidence interval.

What else is worth having open alongside it?

Kruskal-Wallis Test Calculator and Mann-Whitney U Test Calculator — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

Distributions and test statistics are computed from their standard definitions, not from a lookup table, so results carry more digits than a printed table would. The assumptions each test makes are stated with it.

Further reading

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