Enter the number of positive results and the number of tests into the Positivity Rate Calculator. The calculator will evaluate the Positivity Rate. 

Positivity Rate Formula

The following two example problems outline the steps and information needed to calculate the Positivity Rate.

PO = P / T * 100

  • Where PO is the Positivity Rate (%)
  • P is the number of positive results 
  • T is the number of tests 

How to Calculate Positivity Rate?

The following example problems outline how to calculate Positivity Rate.

Example Problem #1:

  1. First, determine the number of positive results. 
    • The number of positive results is given as: 30.
  2. Next, determine the number of tests. 
    • The number of tests is provided as: 60.
  3. Finally, calculate the Positivity Rate using the equation above: 

PO = P / T * 100

The values provided above are inserted into the equation below and computed.

PO = 30 / 60 * 100 = 50.00 (%)


Example Problem #2: 

For this problem, the variables required are provided below:

number of positive results = 50

number of tests = 60

Test your knowledge using the equation and check your answer with the calculator..

PO = P / T * 100 = ?