Standard Error of Regression CalculatorFormula

## Standard Error of Regression (RMSE)

The standard error of regression (also called residual standard error or RMSE) estimates the standard deviation of the residuals.

### Formula

**Se = sqrt(SSE / (n - p - 1))**

where SSE is the sum of squared residuals, n is sample size, and p is the number of predictors. Smaller Se means better prediction accuracy. The denominator (n - p - 1) accounts for the degrees of freedom lost estimating the model parameters.

Esempio Risolto

SSE = 200, n = 50, p = 2 predictors.

  1. df = 50 - 2 - 1 = 47
  2. MSE = 200 / 47 = 4.2553
  3. Se = sqrt(4.2553) = 2.0629