😷 Mask vs No Mask Calculator
Compare an estimated relative exposure risk with and without masks, based on commonly cited mask filtration effectiveness ranges for the infected person and the person nearby.
How masks reduce exposure risk
Masks can reduce respiratory infection risk in two ways: source control (reducing the respiratory droplets and aerosols an infected person releases) and personal protection (reducing what the wearer inhales). Combining a mask on the contagious person with a mask on the other person compounds the protection.
How this calculator works
Starting from a baseline exposure risk percentage you choose (representing risk for a specific close-contact situation with no precautions), the calculator applies illustrative filtration/effectiveness reductions commonly cited in public health literature for cloth masks, surgical masks, and well-fitted N95/KN95 respirators, applied independently to the source and the receiver.
Real-world effectiveness varies widely with fit, fabric, duration and proximity of exposure, ventilation, and viral load, so treat these numbers as illustrative comparisons rather than precise predictions. This tool is for general educational purposes only and does not replace guidance from public health authorities.