Diagnostic Test Calculator
This test calculator evaluates how well a laboratory or rapid screening test performs by translating raw outcome counts into sensitivity, specificity, predictive values, and overall accuracy. By entering the observed numbers of true positives, false positives, true negatives, and false negatives, quality teams can understand whether a diagnostic protocol needs recalibration, additional quality control, or more samples.
The test calculator interprets:
• Sensitivity (true positive rate) to show how often disease cases are captured.
• Specificity (true negative rate) to show how reliably non-cases are cleared.
• Positive and negative predictive values so clinicians know how much to trust each result.
• Overall accuracy to summarize performance across the entire tested population.
Example: A respiratory virus assay reported 220 true positives, 25 false positives, 255 true negatives, and 18 false negatives over one week. Plugging these counts into the test calculator yields sensitivity of 92.44%, specificity of 91.08%, positive predictive value of 89.81%, negative predictive value of 93.40%, and accuracy of 91.74%. These realistic numbers make it clear the assay is dependable but may still miss a handful of early infections, prompting labs to combine it with clinical judgment.
Deploy this test calculator after every validation batch to ensure drift in reagents or sampling techniques is detected early. Regular monitoring keeps reported case numbers credible and helps public health teams respond with confidence.