For a moment, let's assume the case count doubles every 3 days. This is reasonable as it appears to be somewhere between 2 and 4 days. 30 days represents 10 doubles or 2^10 = 1024. The US cases today are around 31,000. That means in 30 days, there will be 31,744,000 cases.
Do the math.
Here's a week's data from github https://github.com/CSSEGISandData/COVID-19 of the confirmed cases for the US. I'll leave it to you to figure out the doubling rate (hint - it's less than 3 days). I picked 3 because the arithmetic was simple.
3/15 3499
3/16 4632
3/17 6421
3/18 7786
3/19 13680
3/20 19101
3/21 25493
Cool site.
That's very good that few people are on the streets. Half of the US cases are in New York state. Keep it up and we might get a handle on it fairly quickly.