🧀 Coronavirus Protection – Swiss Cheese Model Calculator
The ‘Swiss Cheese Model’ shows how stacking several imperfect protective measures together closes more gaps than relying on just one. Pick which layers you use to see an estimated relative risk reduction.
What is the Swiss Cheese Model?
The Swiss Cheese Model is a way of visualizing layered defense: picture each protective measure as a slice of cheese full of holes (its weaknesses). Any single slice lets some risk through, but when you stack several slices together, the holes rarely line up, and much less gets through overall.
How this calculator works
Each layer you select (mask, distancing, ventilation, vaccination, testing, and hand hygiene) is assigned an illustrative, independent risk-reduction percentage based on commonly cited public health ranges. The calculator combines them multiplicatively, meaning each additional layer reduces what’s left of the risk, rather than simply adding up percentages, so no single layer needs to be perfect for the combination to be effective.
These percentages are simplified, illustrative estimates meant to demonstrate the layered-protection concept, not precise clinical or epidemiological predictions for any individual situation. This tool is for general educational purposes only and does not replace guidance from public health authorities or healthcare professionals.