A diagnostic evaluation tool

Confusion Matrix Calculator

Also known as an error matrix. Enter the four cells of a 2×2 confusion matrix to compute precision, recall, specificity, NPV, MCC, F-beta, and the full family of derived diagnostic statistics.

01

Enter the matrix

Predicted condition
Positive
Negative
Actual +
Actual −
Quick examples
02

Derived statistics

Total samples:

Positive class metric Negative class metric
Accuracy ACC
(TP + TN) / N
Matthews CC MCC
(TP·TN − FP·FN) /
√((TP+FP)(TP+FN)(TN+FP)(TN+FN))
F-β score F1
(1+β²)·P·R / (β²·P + R)

Predictive values

+Precision PPV
TP / (TP + FP)
Neg. Pred. Value NPV
TN / (TN + FN)
+False Disc. Rate FDR
FP / (FP + TP), = 1 − PPV
False Omission FOR
FN / (FN + TN), = 1 − NPV

True and false rates

+Sensitivity TPR, Recall
TP / (TP + FN)
Specificity TNR
TN / (TN + FP)
False Pos. Rate FPR
FP / (TN + FP), = 1 − TNR
+False Neg. Rate FNR
FN / (TP + FN), = 1 − TPR

Distribution and error

+Positive prevalence
(TP + FN) / N
Negative prevalence
(TN + FP) / N
Balanced Accuracy
(TPR + TNR) / 2
Error rate
(FP + FN) / N, = 1 − ACC
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