Trevor Bedford, a scientist at the Fred Hutchinson Cancer Research Center, tweets: "Estimating total number of infections is difficult without serology...but I'd guess that we're catching between 1 in 10 to 1 in 20 infections as a confirmed case....This would give 5-10 million infections in the US." Since we're at about 22,000 U.S. deaths attributed to Covid-19 (some say that's an undercount because of people dying at home and not being tested or counted, some say it's an overcount because of people dying of other things but testing positive for this virus, but leave that aside for now), the 10 million infections number would mean that the chances of having died of it if you got it are in the neighborhood of two tenths of a percent, or two out of a thousand.
Again, that doesn't mean you should stop washing your hands or otherwise take the risk of this disease casually. Those who are older or have preexisting health conditions that might render them vulnerable should take particular care. If a two-tenths of a percent crude fatality rate applied to the entire U.S. population of about 330 million, it would mean about 660,000 deaths, which is more than died in 2017 from either heart disease (647,457) or cancer (599,108). But Bedford also says herd immunity kicks in once between 50% and 66% of the population is infected. I take that to mean that the 660,000 scenario is unlikely.
Another way of looking at this is to take the University of Washington model, which has jumped around a lot to the point where some people don't think it's worth paying much attention to but which for what its worth right now is predicting about 61,000 Covid-19 deaths in the U.S. by August 1, or a range of between about 26,000 and 155,000. Sixty-one thousand deaths may seem like a lot of deaths—the equivalent of 20 September 11 attacks. But as a percentage of the U.S. population of roughly 330 million, it's about two hundredths of a percent, or a two out of ten thousand chance of dying of the disease. If you are young and in good health, your chances are probably even less. Anyway, it may not be a chance that you or I want to take, especially if "not dying" might still mean being stuck in a hospital with no visitors feeling miserable for weeks. But if the alternative is being stuck at home for 12 to 18 months, it's going to be a chance that people increasingly weigh on their own.