The school gives an out of level computerized test 2-3 times per year and I have a norms chart that show the quartiles for each grade and season. So I looked at DD's score (not the percentile but the raw score) and saw that it's the same as what the average 8th or 9th grader scores. After around 6th grade, though, the scores really slow down and go up a tiny amount each year. So it's hard to get accurate information. There are not enough test questions at the higher levels. There is also a "suggested learning objectives" report which shows the standards the kid has mastered and what they should work on next, and it lists the grade level. So for DD, most of the things on the report were at an 8th or 9th grade level. However, there are huge gaps and I know she has not mastered all the concepts before 8th or 9th grade. The test doesn't pick that up due to the child guessing correctly, not enough questions, or whatever. Since that test also uses national percentiles, it would be reasonable to assume that your DD is at the same grade equivalent.
I don't know what happens with your test, but with ours, it is possible for the computer to run a grade equivalent score. We never actually get that though (the school probably doesn't want parents freaking out thinking their kids should do a triple grade acceleration).
