It is widely acknowledged that the reported numbers of infected cases with COVID-19 were not complete. A structured approach is proposed where we distinguish cases reflected later in the numbers of confirmed cases and those with mild or no symptoms thus not captured by any systems at all. The number of infected cases in the US is estimated to be 220.54% of that reported as of Apr 20, 2020. This implies an overall infection ratio of 0.53%, and a case mortality rate at 2.85% which is close to the 3.4% suggested by WHO in March 2020.