# False Positive Rate Calculation

A person who incorrectly receive a positive test result is false positive rate. You can calculate your false positive rate and true negative rate based on the specificity and prevalence using False positive percentage calculator. Specificity is the percentage of healthy individuals who correctly receive a negative test result. False positive rate is also known as false alarm rate. In others words, it is defined as the probability of falsely rejecting the null hypothesis for a particular test.

## False Positive Percentage Calculator

A person who incorrectly receive a positive test result is false positive rate. You can calculate your false positive rate and true negative rate based on the specificity and prevalence using False positive percentage calculator. Specificity is the percentage of healthy individuals who correctly receive a negative test result. False positive rate is also known as false alarm rate. In others words, it is defined as the probability of falsely rejecting the null hypothesis for a particular test.

Code to add this calci to your website

#### Formula:

FalsePositive = (1 - Specificity) x (1 - Prevalence)
TrueNegative = Specificity x (1 - Prevalence)
FalsePositiveRate = 100 * FalsePositive / (FalsePositive + TrueNegative)

#### Example

**The specificity and prevalence of a disease is 0.8 and 0.2 fraction, then **

False Positive = (1 - 0.8) x (1 - 0.2)

= 0.16 ratio

True Negative = 0.8 x (1 - 0.2)

= 0.04 ratio

False Positive Rate = 100 x 0.16 / (0.16 + 0.04)

= 80 %