One-Way ANOVA Calculator
Perform a one-way Analysis of Variance (ANOVA) online. Enter group data, get F-statistic, p-value, and full ANOVA table. Free statistics tool.
Enter data for each group, one value per line. Click "Add Group" to add more groups (minimum 2 required).
What Is One-Way ANOVA?
One-way ANOVA (Analysis of Variance) is a statistical test used to compare the means of three or more independent groups. It determines whether there is a statistically significant difference between group means by analyzing the variance within and between groups. The null hypothesis states that all group means are equal.
How to Interpret the Results
The F-statistic measures the ratio of between-group variance to within-group variance. A larger F-statistic indicates greater differences between groups. The p-value tells you the probability of observing your results if the null hypothesis were true. A p-value below 0.05 is typically considered statistically significant, meaning at least one group mean is significantly different from the others.
Assumptions of ANOVA
ANOVA assumes that observations are independent, each group's data is approximately normally distributed, and variances across groups are approximately equal (homogeneity of variance). Violations of these assumptions may affect the reliability of the results. For non-normal data, consider the Kruskal-Wallis test as an alternative.
When to Use ANOVA vs Other Tests
Use one-way ANOVA when comparing 3+ groups with one independent variable. For 2 groups only, a t-test is more appropriate. For 2+ independent variables, use two-way ANOVA. If your data violates normality assumptions, use the Kruskal-Wallis non-parametric test instead.