What grade level do i perform at?

Im 13 and in 7th grade. Now i know you can't fully evaluate but i will give you things that could help you ess maybe an estimated grade level. I can read at 12th grade reading level. Out of my schoo's best spellers, i got third place and my school hold 6th, 7th, and 8th graders. I know more about the first eon (precambrian period) and the first and second subdivision of the paleozoic era AND the earth AND the universe better than my brother at college. He goes to Notre Dame. Im not as smart in math, i would say im around my grade level, and in social studies, my teacher already told me that im perform around a 9th grade level. I know Habilis is our first descendent of Sapiens sapiens which is our subdivision. But we are more directly related to erectus. The first life was found in the Archaean part of the pre cambrian, and in plentiful amounts in the proterzoic. Now i could go on and on, but you probably get the point