ANOVA Calculator (One-Way)
Compare three groups at once with F, p and eta squared.
Enter your values
Enter the group 1 values you are working with.
Enter the group 2 values you are working with.
Enter the group 3 values (optional) you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- 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
At a glance
| What it does | Compare three groups at once with F, p and eta squared. |
|---|---|
| Category | Statistics |
| Inputs needed | Group 1 values, Group 2 values, Group 3 values (optional) |
| Main output | F statistic |
| Formula | F = MS_between ÷ MS_within |
| Cost | Free — no sign-up, no download |
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.
Inputs explained
- Group 1 values
- Enter the group 1 values you are working with.
- Group 2 values
- Enter the group 2 values you are working with.
- Group 3 values (optional)
- Enter the group 3 values (optional) you are working with.
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.
What do I need to enter into the ANOVA Calculator (One-Way)?
Just 3 values: group 1 values, group 2 values, group 3 values (optional). Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the ANOVA Calculator (One-Way) work out the 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. It applies the formula F = MS_between ÷ MS_within and shows the working so you can check each step by hand.
Is the ANOVA Calculator (One-Way) free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.