In New York City about 0.15% of the entire population of the city have already died from the virus, putting a lower limit on the IFR.
Estimates of the IFR have been consistently between about 0.5% to 1% by most authorities I have confidence in.
And calculate that IFR per age band. Running WA numbers in https://news.ycombinator.com/item?id=23080035 shows that the IFR here ranges from .7% to 15%(!) if you do that.