R-Squared Calculator — Formula
## R-Squared (Coefficient of Determination)
R² measures the proportion of variance in the dependent variable that is explained by the regression model.
### Formula
**R² = SSR / SST = 1 - SSE / SST**
where SSR is the regression sum of squares, SST is the total sum of squares, and SSE is the residual sum of squares. R² ranges from 0 (model explains nothing) to 1 (perfect fit).
R² measures the proportion of variance in the dependent variable that is explained by the regression model.
### Formula
**R² = SSR / SST = 1 - SSE / SST**
where SSR is the regression sum of squares, SST is the total sum of squares, and SSE is the residual sum of squares. R² ranges from 0 (model explains nothing) to 1 (perfect fit).
Exemplo Resolvido
A regression with SSR = 800 and SST = 1000.
- R² = 800 / 1000 = 0.80
- The model explains 80% of the variance in y.
- SSE = 1000 - 800 = 200
- R = sqrt(0.80) = 0.8944