Actual Planet Calculator

Clicked on this website after a bit of fruitless searching and thought I had finally found the end of the tunnel... and, no, it was not the end of the tunnel, but instead the starting point for an extremely tedious obstacle course and the light I saw was just a circus ring on fire. To prevent others from wanting to die inside as I do, it would be nice for there to be a calculator that "knows" all the numerical values for some planets, the sun, and maybe a couple of moons so we could divide, subtract, et cetera to our hearts' content. Yeah, maybe the tunnel had a side door somewhere in the middle where I could just look the numbers up myself and do some manual math, but... yeah, I have no excuses. Moving on...
The problem I had encountered was that I needed to know how large the Earth would be if I took away a bunch of mass that was equal to 30 moons. So, yeah, a calculator that could solve that for me. Thanks to anyone who read this whole thing, and the one dude who decides to make this, if ever. Cheers.