This paper presents the first analytical model for calculating how many tests and tracing needed to suppress COVID-19 transmission. The number of people needs to be tested daily is given by:




This model provides insights and guidance for public health practitioners to deploy the testing and tracing resources accurately and optimally. An Excel sheet is attached to facilitate easy calculation of the number of tests and tracing needed. This analytical model applies also to any infectious disease that can be suppressed by deploying testing and tracing.