I had trouble figuring out how to take the standard deviation and mean of a bell curve, give it a value, and come out with a percentile. Luckily, the jStat library has this built in! Which requires javascript, so I made this page to make it easy. No Z-Scores needed to figure out the percentile from a value here! And if you want to calculate two at the same time and get overlapping percentiles/odds, I adapted this calculator for two at the same time here

What do all these pre-filled numbers mean? Oh nothing, really, just random filler data ;)