April 10, 2020 / LAUREN SOMMER
As coronavirus numbers have ticked steadily upwards in some U.S.states and cities, officials have watched one specific figure to see whether they’re facing a flattening curve or runaway outbreak: the doubling rate.
Simply put, it’s how many days it takes for the number of coronavirus cases, hospitalizations or deaths to double. The shorter the time frame, the steeper the curve and the faster the growth. 
In an encouraging sign, health officials in several states are starting to see doubling rates slow, which means the curve is flattening. Hospitalizations and deaths are still growing, but not as quickly.
As New York’s outbreak has heated up, Gov. Andrew Cuomo often refers to doubling times to signal how things are going.”We had a doubling of cases every two days,” he told the public on March 30. “We now have a doubling of cases every six days. So while the overall number is going up, the rate of doubling is actually going down.”
This past week, New York City’s doubling rate for new cases has fallen to approximately every eight days, as of Thursday. Though deaths continued to rise, Cuomo says new hospitalizations may have reached a plateau.