Just a reminder, that tool likely underestimates the risk of covid. Seroprevalence data shows undercounting of up to 24 times (rather than the 5 or 10 this tool shows.)

Also, this tool assumes you are only seeing people from your county.

And humans are terrible at assessing compound risk. If the tool shows a 5% risk from a gathering, people will likely attend multiple events. ("Oh, it's only 5% to go to Thanksgiving. And 5% to go to Friendsgiving. etc.") When you consider multiple events, risk doesn't stay constant.

So while that tool is interesting, don't look at it as a mechanism to say, "Yeah, it's probably ok to have a gathering."