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Updated 2026-03-07 UTC
Adjusted R² Calculator — Penalized Fit Metric — GetCalcMaster
Compute adjusted R²: 1 − (1−R²)·(n−1)/(n−p−1). Useful when comparing models with different numbers of predictors.
Adjusted R² modifies R² by penalizing extra predictors. It can decrease when you add a predictor that doesn’t improve fit enough, making it useful for in-sample model comparison.
Important: Educational. For predictive modeling, prefer cross-validation metrics.
What this calculator is
The Statistics Calculator is an interactive tool inside GetCalcMaster. It’s designed to help you explore scenarios, understand formulas, and document assumptions.
Key features
- Explicit penalty for number of predictors p
- Can decrease when adding weak predictors
- Simple formula from R², n, and p
Formula
Adjusted R² = 1 - (1 - R²) * (n - 1) / (n - p - 1)Quick examples
If n is small and p is large, the penalty term is stronger.If adding a predictor barely reduces SSE, adjusted R² may drop.
How to use it (quick steps)
- Compute R² for your model.
- Count n (observations) and p (predictors, excluding intercept).
- Compute adjusted R² using the formula below.
- Compare models: higher adjusted R² suggests better in-sample tradeoff.
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FAQ
Is this calculator official?
No. GetCalcMaster provides educational estimates and learning tools. Always verify against official definitions, documents, or professional advice.
Do you store my inputs on the server?
No. Calculations run locally in your browser. Optional remember/restore features (if enabled) use local browser storage.
Tip: For reproducible work, save your inputs and reasoning in Notebook.