Rough measurement with measuring tape, then trial and error till I got what I needed(got better the more bends I did). There were more than a few errors (bad measurment, over heat acrylic). In the end I have 12' of acrylic left from the 30' I bought originally.
Thanks, I actually tried on this one lol. Still some things I would like to change (custom PSU cables for one) but had to stop spending money on it.