Adjusted R-squared calculator
Enter ordinary R², the observation count and the number of predictors excluding the intercept.
How to use this page
- Enter model R².
- Enter n and predictor count.
- Compare R² with adjusted R².
What this page does not do: The formula assumes a model with an intercept. It does not test regression assumptions or prediction quality.
Further reading
R² never decreases when another predictor is added, even when that variable contributes little. Adjusted R² accounts for predictor count and sample size, making it more useful for comparing nested models with the same outcome Y.
The value can be negative when the model performs worse than the mean-only baseline after the complexity penalty.
Frequently asked questions
Does the intercept count as a predictor?
No. Enter the number of explanatory variables without the intercept.
Why is adjusted R² lower?
The formula penalizes predictor count relative to the observations available.
See also
ACF and PACF autocorrelation calculator
Calculate ACF and PACF across time-series lags. Review the chart, reference bounds and coefficient table.
Beta distribution calculator
Calculate beta density, CDF, upper tail and quantile together with its mean and variance.
Bonferroni correction calculator
Adjust alpha and p values with the Bonferroni method. Inspect the corrected threshold and decision for every t