Enter the number of true positives, true negatives, and total samples into the calculator to determine the accuracy of a test.

## Accuracy Formula

The following formula is used to calculate the accuracy of a test.

A = ( TP + TN ) / S
• Where A is the accuracy
• TP is the true positives
• TN is the true negatives
• S is the total number of samples

To calculate the accuracy of a test, sum the true positives and true negatives, then divide by the total number of samples.

## Accuracy Definition

Accuracy is defined as the measure of how many tests it takes to achieve a correct result.

## Accuracy Example

How to calculate accuracy?

1. First, determine the number of true positives.

Add up the total number of true positives produced by the test.

2. Next, determine the number of true negatives.

Add up the total number of true negatives produced.

3. Finally, calculate the accuracy.

Calculate the accuracy by summing the true negatives and positives and then dividing by the total number of samples (total number of tests performed)

## FAQ

What is accuracy?

Accuracy is a measure of a test’s ability to achieve the correct result. For example, if a certain test should yield a value of 10, but the actual results in a value of 9, the accuracy is 9/10 = .90 = 90%.

When is accuracy used?

Accuracy is most often used in the medical field when analyzing how correct a specific test is.