BALTIMORE (WJZ) — What are your chances of contracting COVID-19?

One professor at John Hopkins University has come up with an equation that calculates the risk of getting the virus.

Professor Rajat Mittal is the co-author of the formula. It’s called The Contagion Transmission Inequality, or CAT Inequality for short.

It’s made up of 10 variables like breathing rates, the environment a person is in and the amount of time spent near somebody who’s infected.


“This equation tells you what the variables are that you can control in your behavior in the way you go about doing things,” Mittal said.

The formula found doubling one’s distance from an infected person can cut the risk of getting the virus in half.

It also found, if everyone wore an N95 mask, the risk of transmission goes down dramatically to a less than 1% chance of getting the virus

“That’s huge,” Mittal said. “That tells you how masks are incredibly important.”

Mittal said the model can be used by everyone and could help make better decisions to reduce the risk of getting infected.

“Scientists are trying to figure out these variables and policy-makers hopefully are trying to take that information and develop better policies,” he said.

To look at the entire formula, click here.

For the latest information on coronavirus go to the Maryland Health Department’s website or call 211. You can find all of WJZ’s coverage on coronavirus in Maryland here.

Stetson Miller


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