As shown above, the Root Mean Squared Error (RMSE) is the root mean squared error deviation that is determined by the square root of the Mean Squared Error (MSE). Generally, the RMSE is used to calculate the difference between the actual values and the predicted value of the model. the RMSE represents the standard deviation of the difference between the predicted values and the actual values. It is preferable that the value of the RMSE be low (cigar).