Variance Inflation Factor Calculator
Translates an auxiliary regression R² into the variance inflation associated with predictor collinearity. The form displays VIF = 1/(1−R²aux) beside variance inflation factor, using a worked condition that can be recalculated with the labeled inputs.
Describe the observed data during an independent check
Variance inflation factor
The question behind variance inflation factor
The variance inflation factor page translates an auxiliary regression R² into the variance inflation associated with predictor collinearity.
Variance inflation factor is limited to the statistical quantity named by the result panel. The variance inflation factor calculation does not silently add a population, time horizon, causal direction, or decision threshold that is absent from the fields.
Measurements required for variance inflation factor
- Auxiliary R squared: For variance inflation factor, the worked value for auxiliary r squared is 0.75 ratio. Treat the auxiliary r squared entry (0.75 ratio) explicitly as a count, proportion, rate, estimate, or model parameter before comparing variance inflation factor conditions. The form enforces minimum 0, maximum 0.999999.
The entries used for variance inflation factor must refer to one coherent analysis condition. Combining incompatible populations, periods, or measurement definitions can produce valid variance inflation factor arithmetic for a nonexistent study.
The arithmetic used for variance inflation factor
For variance inflation factor, match every symbol in the relationship to a labeled field before substituting numbers. Variance inflation factor is reported in ratio.
While checking variance inflation factor, inspect every denominator in VIF = 1/(1−R²aux). For variance inflation factor, a zero or near-zero denominator can make variance inflation factor undefined or unstable.
Worked values for variance inflation factor
The default variance inflation factor condition is Auxiliary R squared = 0.75 ratio.
An auxiliary R² of 0.75 gives VIF=4.
The live calculator reports Variance inflation factor 4 · Auxiliary R squared 0.75. Repeating one intermediate step from VIF = 1/(1−R²aux) provides a fixed variance inflation factor reference check for later code changes.
What the variance inflation factor arithmetic assumes
A VIF is a diagnostic whose interpretation depends on design, scaling, and the other predictors; no universal cutoff proves a problem.
For variance inflation factor, a fitted coefficient or association is conditional on the model and observed range; it does not by itself show that changing one variable will cause another to change.
When variance inflation factor can mislead
When interpreting variance inflation factor, inspect residual behavior, influential observations, nonlinearity, dependence, and extrapolation before carrying a regression result to a new setting.
As a second check for variance inflation factor, reversing the numerator and denominator answers a different question, so retain the direction printed in VIF = 1/(1−R²aux).
When the analysis changes, compare regression f statistic and partial correlation.
Testing how stable variance inflation factor is
Change auxiliary r squared while holding the remaining entries fixed, then state why the direction and size of the variance inflation factor change are plausible from VIF = 1/(1−R²aux).
Repeat the variance inflation factor exercise with auxiliary r squared. If a modest defensible change materially alters the interpretation, report both conditions rather than presenting that variance inflation factor scenario as exact.
Where a plausible variance inflation factor can go wrong
Before accepting variance inflation factor, compare every entered value with its label, unit, and allowed domain after reading the printed relationship from left to right.
For variance inflation factor, do not move a number between fields merely because the units look compatible; each label gives the number a different statistical role.
Another variance inflation factor failure occurs when a rounded output is reused as though it were the original measurement. Carry guard digits through calculations that depend on variance inflation factor, then round only the reported value.
A reproducible record of variance inflation factor
Report variance inflation factor using VIF = 1/(1−R²aux), followed by the entered values, units, exclusions, and analysis date. Name the variance inflation factor population or dataset boundary instead of leaving it implicit.
Keep the full calculator output with the record, including Variance inflation factor 4 · Auxiliary R squared 0.75. A later variance inflation factor review can then distinguish a changed input from a different convention or software implementation.
Questions about variance inflation factor
Why could another program report a different variance inflation factor?
A different convention for rounding, tails, ties, interpolation, parameterization, or missing values can change variance inflation factor. Compare the printed variance inflation factor formula and its input definitions before treating either output as wrong.
What does variance inflation factor represent on this page?
It is the quantity produced by VIF = 1/(1−R²aux) from the displayed auxiliary r squared. This page translates an auxiliary regression R² into the variance inflation associated with predictor collinearity.
What should be saved with variance inflation factor?
Save the entered values and units for auxiliary r squared, along with the analysis date, exclusions, software or formula version, and the relationship VIF = 1/(1−R²aux). That record is sufficient to rebuild this specific variance inflation factor calculation.
Does variance inflation factor establish a causal or population conclusion?
No. The displayed variance inflation factor value is conditional on the entered data and named method. The variance inflation factor design, measurement process, and assumptions determine what can be concluded beyond those values.