One-way ANOVA calculator
Compare the means of two or more groups with an F test and an ANOVA table.
A clear answer. Here’s how.
Splits total variation into between-group and within-group sums of squares. F = (SSB ÷ (k − 1)) ÷ (SSW ÷ (N − k)) and the p-value is the upper tail of the F distribution. η² = SSB ÷ SST is the share of variance explained by group. Assumes independent observations, approximately normal residuals and similar group variances; unequal group sizes are allowed. A significant result does not say which groups differ.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Groups, one per line as “name: values”
Group A: 6, 8, 4, 5, 3, 4 Group B: 8, 12, 9, 11, 6, 8 Group C: 13, 9, 11, 8, 7, 12
Example result
| Source | Sum of squares | df | Mean square | F | p-value |
|---|---|---|---|---|---|
| Between groups | 84 | 2 | 42 | 9.26470588235 | 0.00239877732939 |
| Within groups | 68 | 15 | 4.53333333333 | ||
| Total | 152 | 17 |
Group means: Group A 5 (n = 6); Group B 9 (n = 6); Group C 10 (n = 6). Assumes independent observations, roughly normal residuals and similar variances between groups. A significant F says only that at least one mean differs; follow up with a post-hoc test to find which.