Hello everyone!

I wanted to let you all know that I've developed a very unofficial, approximate conversion chart for converting raw scores to scaled scores and percentages, both for the current test and for the five officially released practice tests.

https://www.mathsub.com/wp-content/uploads/2019-mathsub-conversion-chart.pdf

I arrived at these charts by compiling a bunch of official data (both the Interpretive Data charts released by the ETS and people's posted scaled score/percentile pairs on here), comparing the tables at the end of the official practice tests, doing a bunch of linear regression, and making a few educated guesses here and there. The chart attempts to take into account the "difficulty creep" of the test over the years.

Again, this chart is very unofficial and approximate. On the real thing, the difficulty is slightly different every time (depending on what form you have), so the actual conversion will vary. Nobody knows the true conversion formulas except the ETS --- this is just my best guess.

Please let me know if this helps, or if you have any suggestions for how to make it even better!