🎯 Accuracy Calculator
Measure how well a classifier or test performs. Enter your true positive, true negative, false positive, and false negative counts to get accuracy, precision, recall, and F1 score.
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What This Calculator Does
This calculator measures how well a classification model, diagnostic test, or prediction system performs, using the standard confusion-matrix counts: true positives, true negatives, false positives, and false negatives.
The Formulas
- Accuracy = (TP + TN) / (TP + TN + FP + FN)
- Precision = TP / (TP + FP)
- Recall = TP / (TP + FN)
- F1 Score = 2 × (Precision × Recall) / (Precision + Recall)
Accuracy alone can be misleading when the classes are imbalanced (for example, when negative cases vastly outnumber positive ones), which is why precision, recall, and F1 are shown alongside it for a fuller picture. This tool is for general educational and analytical use.
Last reviewed August 2026