If you want to know how your round is rated, here is a rough way to estimate, it seems to work, within plus or minus 10 pts.
In a typical Iowa local tourney the hot round is about 1000-1020 rated. And each shot is going to be about 8-10 rating points. So if the hot round is a 45, then you can estimate that a 55 is probably rated about 910.
1000-(9pts x 10 shots)=910
This works for 18 hole courses with typical par. Longer courses (more holes or higher par) will make each shot worth fewer rating points. Short courses with lots of deuces will make each shot worth more rating points.