How do I determine my PSAT scores?

I received a 60 in critical reading, a 39 in math, and a 56 in Writing skills. Mind you, I am only a sopre and I have not yet taken geometry. this is why my math score is so low. It says I scored in the 66th percentile. What would be my overall score? I really want to know because I need to improve to get into NYU, my first choice university.