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One-Way ANOVA

Full ANOVA table, pairwise post-hoc t-test p-value matrix with Bonferroni guidance, and a group chart with publication-style significance brackets. The same math as the Excel workbook, live in your browser.

What this is for: Compares means of up to 5 groups with a full ANOVA table, pairwise post-hoc comparisons with Bonferroni guidance, and a chart with automatic significance brackets.

The formula: F = MS(between groups) ÷ MS(within groups)

How to use:

  1. Rename the groups if you wish, then paste each group's values into its box, one value per line (up to 15 per group); leave unused groups blank — they are ignored.
  2. Read the ANOVA table — F, p-value and significance — to see whether the group means differ overall.
  3. Check the pairwise p-value matrix against the Bonferroni alpha shown (0.05 divided by the number of comparisons) before calling a pair different.
  4. Use the bracket-label control to show Bonferroni-adjusted stars or exact p-values on the group chart.

One-Way ANOVA — up to 5 groups × 15 values

The full ANOVA table is computed from cell formulas in the workbook (no Analysis ToolPak needed). Rename groups freely; blank groups are ignored. One value per line.

Grand mean
Groups / total N /

ANOVA table

SourceSSdfMSFp-value
Between groups
Within groups (error)
F statistic
p-value
Significance
Bonferroni alpha (0.05 / comparisons)
Number of pairwise comparisons

Post-hoc: pairwise two-tailed t-test p-values (Student, TTEST type 2)

Bonferroni: with k groups there are k(k−1)/2 comparisons — judge each p against 0.05 / (number of comparisons).

Prefer to work offline or keep a copy? The download link is right below.
Download the One-Way ANOVA workbook (.xlsx)
Notes & limits (from the workbook): The pairwise matrix is a simple post-hoc stand-in for Tukey's test: unadjusted two-tailed Student t-tests (Excel TTEST type 2), judged against the Bonferroni alpha shown. Bracket stars on the chart use Bonferroni-adjusted p-values (raw p × number of comparisons). Assumes independent groups; blank cells/groups are ignored, exactly as in the workbook.