This is one of the links that appears on Tomas Pueyo's "The Hammer and The Dance" website, and appears to be an elegant rendering of standard epidemiological math. You can adjust the eleven sliders and change the graph as you go. Be careful if you don't understand the underlying math, though, as you can get counter-intuitive results that may be wildly off. I found it a sobering experience, that shifted my focus about the difference we each will make by our simplest actions