It is hard to estimate how our daily activities contribute to contracting COVID-19. How risky is a 60-minute trip to the supermarket? How about a presidential debate with a known infected individual? The Microcovid Calculator is a simple tool to calculate risk based on published scientific literature on transmission. It outputs risk in the form of MicroCOVIDs where where 1 microCOVID is equivalent to a one-in-a-million chance of getting COVID-19. It’s pretty useful.
For instance, let’s say you want to understand the risk that Joe Biden took being on stage with Donald Trump, who was likely infected during their debate. using the Microcovid Calculator you enter the location of an activity, the number of people, and their relative risk level to get a result. Depending on whether you think the debate was conducted using normal conversation or Loud talking (shouting, talking over music, singing), the estimate moves from 20,000 MicroCOVIDs to >100,000 microCOVIDs, or a 2% chance of contracting COVID-19 to >10%.

The tool also comes with some nice presets, such as shopping for 60 minutes in a grocery store, voting with a mask on, or going to a bar. It also pulls the latest reported data on infection rates across the United States to give you actionable estimates as the pandemic progresses. At this point in time, voting in North Dakota is equivalent to 9 microCOVIDs or 1 microCOVID here in San Mateo county.

The tool was developed by the members of the Ibasho community, a communal house in San Francisco. The tool came out of necessity as members of the household needed to assess how risky various behaviors were for its members. The SF Chronicle has a nice piece on how intentional communities in San Francisco are managing the pandemic and how this led to the development of the tool.
Hats off for this super useful tool!