It was inspired by How long is my schlong? and abovethemeans' volume calculator. The former website, HLiMS for short, had a few issues which I wanted to fix in calcSD, mainly the fact that it looks up percentages in a fixed table for every 0.2 increment (meaning values in between are rounded downwards), but also that it uses outdated data from an old research, Hungfun's Average (which is an option in calcSD only for the sake of comparing). That said, abovethemean's calculator has a better method to calculate the volume values which sadly is not an option for calcSD due to also being compared against a fixed table generated using the R programming language.
I tried making it as lightweight as possible while still looking modern and having a lot of functionality, but please excuse me for any design flaws, I'm still learning. I value privacy, so absolutely no data is collected when you visit the site or make any calculations in it, at least, none I can control. I have no way to tell how many people, if any, even visited this page. Want to yell at me for whatever reason? Go here! that's the feedback page, pls don't actually yell at me