COVID-19 Calculator Quantifies Your Risk Of Getting Sick From Different Activities

A group of volunteers in San Francisco has developed a risk calculator that quantifies your relative risk of getting the coronavirus based on specific activities.

The microCOVID calculator allows you to input information about a specific activity such as location, indoor or outdoor setting, number of people present and duration. The calculator will then tell you your risk in “microCOVIDs.”

“A microCOVID is a 1 in a million chance of getting COVID,” explained Josh Oreman, a member of the microCOVID Project.

He says the project came about because he and some of the other members live together in a group house where they were having trouble managing their individual social bubbles and behaviors while taking into account the rest of the group.

So they developed this tool to help them quantify and track the risk that they were exposing the rest of their household to the virus.

“First we estimate the likelihood that the person you’re interacting with has COVID. And then we estimate the chance that if they have COVID, they would give it to you based on the kind of interaction you’re having,” said Oreman. “Things like wearing masks or being indoors versus outdoors or how long you’re doing it or how many people are there, those all speak to the second part or activity risk.”

The person risk is calculated based on the prevalence of COVID-19 in your area and the other person’s risk profile, which is influenced by their job, household and level of socialization.

For example, a San Francisco resident who wants to have a masked, socially distanced hour-long get together with two friends who both live only with their partners and do not otherwise leave their homes would face a risk of just 0.03 microCOVIDs. But if the friends are essential workers, then the risk increases to 7 microCOVIDs.

Oreman says both of those scenarios are still relatively low risk. On the other hand, a five-hour plane ride where passengers are socially distanced and wearing masks is about 500 microCOVIDs, or a very high risk.
Making that journey every week means that a person’s chance of contracting the virus this year is about 3%.

“That might not sound very high, but that’s a level where it could keep the pandemic going at current levels indefinitely if everyone did this,” Oreman said, stressing that people should look at the risk of all of their behaviors combined, instead of on a case-by-case basis.

While there are no epidemiologists or public health experts involved in developing the tool, the founders include a physician and several academics and is based on existing scientific research on the pandemic.

The project is open-source and feedback or suggestions can be submitted through GitHub.