Classification ROC area calculator

Calculate binary ROC AUC and descending distinct score thresholds with your own figures.

Your numbers

Use the units shown. Results update as you change valid inputs.

Use binary ROC AUC and descending distinct score thresholds to compare changes to your inputs. The method and limits below explain the scope.

Examples

Examples

Try the starting example

Records: unique ID, finite decision score, binary label
A,0.9,1 B,0.8,0 C,0.7,1
Binary ROC AUC
0.5
Descending distinct score thresholds
0.9, 0.8, 0.7
False-positive rates at thresholds
0, 1, 1
True-positive rates at thresholds
0.5, 0.5, 1
Positive and negative record counts
2, 1

Try another scenario

Records: unique ID, finite decision score, binary label
A,0.9,1 B,0.8,0 C,0.85,1
Binary ROC AUC
1
Descending distinct score thresholds
0.9, 0.85, 0.8
False-positive rates at thresholds
0, 0, 1
True-positive rates at thresholds
0.5, 1, 1
Positive and negative record counts
2, 1
Calculation method

Calculation method

Binary ROC AUC

Trapezoid area after moving all tied scores together; ties give half pair credit.

Descending distinct score thresholds

Distinct supplied scores descending.

False-positive rates at thresholds

FP/number of actual negatives after threshold inclusion.

True-positive rates at thresholds

TP/number of actual positives after threshold inclusion.

Positive and negative record counts

Actual positive count, actual negative count.

Symbols and units
a
Records: unique ID, finite decision score, binary label

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions & limits

Assumptions & limits

  • Unweighted binary ROC AUC for supplied higher-is-positive scores; the curve also includes its implicit origin (0,0). No confidence interval, multiclass result or model quality guarantee.
Are these inputs private?

These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.

Further reading

scikit-learn: roc_auc_score ↗

Background reading; this does not imply endorsement or independent review of SumFizz.

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