So I've been meaning to get around to creating this for a while. The idea spawned from my search for a 401(k) calculator that didn't just assume one given future. By that I mean, I wanted a calculator that didn't calculate the return on my investment based on just one average annual return. I wanted a calculator that showed me lots of different futures, based on the standard deviation, a.k.a. the risk, of what I've invested my money in. I want to see the most pessimistic futures, you know the ones where all my investments bite the dust, as well as the most optimistic futures where everything is rainbows and bunny rabbits, as well as everything in between. So in that sense, I wanted a forecaster, not a calculator, similar to the hurricane landfall maps you see on the Weather Channel where the most likely landfall is that red wedge in the middle while wider is an orange wedge and even less likely is the widest yellow wedge. So last week I threw together this 401(k) ...