Statistics

Accuracy Calculator

Find classification accuracy from a confusion matrix.

Calculated Output

Accuracy (%) 85

Formula: accuracy = (TP + TN) ÷ total

Step-by-Step Breakdown

1. Values used:

2. True positives = 80

3. True negatives = 90

4. False positives = 10

5. False negatives = 20

7. Accuracy = 85%

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The math behind it

accuracy = (TP + TN) ÷ (TP + TN + FP + FN). It can mislead on imbalanced data.

80 + 90 correct of 200 → 85%.

Why isn't accuracy always enough?

On rare events, a model can be 'accurate' by always predicting the majority class.