Free Residual Calculator
Calculate the residual (prediction error) for an observation from its actual and predicted values.
Residual (e)
1.5000
Residual (e) vs Actual Value (y)
Regression Residuals
A residual is the difference between an observed value and its predicted value from the regression model. Residuals are the foundation for assessing model fit and detecting problems.
Formula
e_i = y_i - y-hat_i
Positive residuals mean the model under-predicted; negative residuals mean over-prediction. In a well-fitting model, residuals should be randomly scattered around zero with no patterns.
Example Calculation
An observation with actual y = 25 and predicted y-hat = 23.5.
- 01Residual = 25 - 23.5 = 1.5
- 02The model under-predicted by 1.5 units.
- 03Squared residual = 1.5² = 2.25
Frequently Asked Questions
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