To find specificity, divide the number of true negatives by the sum of true negatives and false positives.
Formula:
Contents
S = TN ÷ (TN + FP)
Table of Variables
| Variable | Meaning |
|---|---|
| S | Specificity |
| TN | True Negatives |
| FP | False Positives |
What is a Specificity Calculator | Let's Catch True Negatives With Specificity Calculator 2025
Let’s say you’re testing for a disease — and someone doesn’t have it. The test should say “negative,” right? Specificity tells you how good the test is at catching those true negatives. The Specificity Calculator makes this easy by showing how often the test correctly says “no” when someone really doesn’t have the condition.
This tool is often used in medical stats, research, and lab testing. Pair it with a sensitivity and specificity calculator, a 2 by 2 table calculator, or a PPV calculator for a full picture of how reliable a test really is. Want to check your numbers in Excel? Try the sensitivity specificity calculator Excel version for larger datasets.
And for the developers out there — yes, there’s also a specificity calculator CSS and JavaScript version, but that’s a different kind of specificity! For now, if you want to measure how well a test avoids false positives, this calculator gives you fast, clear, and accurate results.
