ANOVA Calculator (One-Way)
Compare three groups at once with F, p and eta squared.
Enter your values
ⓘ Live results
Results
- F statistic
- 61.5385
- p-value
- < 0.0001
- Verdict
- p < 0.001 — very strong evidence
- Eta squared (effect size)
- 0.911
- df (between, within)
- 2, 12
- Group means
- 6.4 | 10.4 | 14.4
Working
- 1SS between = 160
- 2SS within = 15.6
- 3F = (160/2) ÷ (15.6/12) = 61.538
Quick answer
One-way ANOVA splits total variation into between-group and within-group parts; F = MS between ÷ MS within, and a large F means the group means differ.
F = MS_between ÷ MS_within
How to use the ANOVA Calculator (One-Way)
- 1Enter each group's raw values on its own line of inputs.
- 2Leave group 3 blank if you only have two groups.
- 3Read F and p, then use eta squared to see how much variation the grouping explains.
Worked example
Using the values the calculator loads with:
Inputs
- Group 1 values5, 7, 6, 8, 6
- Group 2 values9, 11, 10, 12, 10
- Group 3 values (optional)14, 13, 15, 16, 14
Results
- F statistic61.5385
- p-value< 0.0001
- Verdictp < 0.001 — very strong evidence
- Eta squared (effect size)0.911
- df (between, within)2, 12
- Group means6.4 | 10.4 | 14.4
- SS between = 160
- SS within = 15.6
- F = (160/2) ÷ (15.6/12) = 61.538
Frequently asked questions
What does a significant ANOVA tell me?
That at least one group mean differs — not which one. Follow up with pairwise t-tests and a correction such as Bonferroni.
What is a good eta squared?
Roughly 0.01 small, 0.06 medium, 0.14 large as a share of total variance explained.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.