Binary Accuracy Calculator: correct predictions, balanced accuracy, sensitivity and specificity from TP, FP, FN and TN.
How to use this tool
- Choose the event or model and review the assumptions below.
- Enter the labeled inputs.
- Select Calculate and read the labeled outputs.
- Change an input and calculate again; Reset restores the example inputs.
Calculation method
(TP + TN) / (TP + FP + FN + TN). Balanced accuracy = (sensitivity + specificity) / 2.
Assumptions and limits
Binary classification with an explicitly chosen positive class. Accuracy measures agreement, not instrument calibration or a guarantee of performance on future data.
Worked example
With TP = 80, FP = 10, FN = 20 and TN = 90, there are 200 observations and 170 correct predictions. Accuracy is 85%. Sensitivity is 80% and specificity is 90%, so balanced accuracy is also 85% for this example. Changing the class mix can separate the two scores. Keep the evaluation population and positive-class definition alongside the result.
Worked reading and practical questions
Browse Statistics calculators or explore other tools on the GreenCalc homepage.
Frequently asked questions
What does this calculator assume?
Binary classification with an explicitly chosen positive class. Accuracy measures agreement, not instrument calibration or a guarantee of performance on future data.
How do I enter and update the inputs?
Use the labeled fields, then select Calculate. Percent fields use 0 to 100. After editing, calculate again; Reset restores the example inputs.