I'm not totally sure what you are looking for. Because the WISC is an ability test, not an achievement test, and it utilizes the newer way of calculating IQ, I don't believe that there are grade or age equivalents. For instance, the older IQ tests used mental age/chronological age x 100 to calculate IQ. That was called a ratio IQ. The newer tests use a deviation IQ formula which simply shows how much a person deviates from the mean of others who are within the same age range but doesn't tell you that you are functioning at the age of someone who is x years old.
I may be totally misunderstanding what you are asking, though! Can you explain more?
