There may be no better non-pharmaceutical intervention for limiting the spread of coronavirus than a face mask. A cloth face covering inhibits the spread of respiratory droplets by the wearer and is also thought to be effective in minimizing the amount of potentially infectious particles that can be inhaled, possibly reducing the severity of the illness.

In an effort to make this dynamic a little less abstract, two Ph.D. students in Poland have created an online calculator that uses statistics and variables to estimate how many infections one person may be able to prevent—and how many lives they might save—as a result of wearing a mask.

Using it is simple. After selecting the option of wearing or not wearing a mask and the mask type—cotton, surgical, or an N95—you can choose the R₀, or rate of transmission, which is set at a default 2.5. This means an infected person will typically spread the virus to roughly two people. You can also choose the percentage of people in the population wearing masks, which affects the rate of infection.

Given a standard set of variables, many people will find that wearing a mask may protect up to 19 people from becoming infected and one person from succumbing to the virus, an estimate based on the mortality rate.

The students, Dominik Czernia and Joanna Michalowska, hope the calculator will raise awareness of the value and effectiveness of wearing a mask in public.

[h/t Popular Mechanics]