Hi student,

Percentile score is a measure of the percentage of total students who appeared for the examination secure rank behind you. For example, if your percentile score is 90, then 90 percent of the total students who appeared for the examination are behind you. However, you cannot calculate marks using the percentile score, for knowing your marks, you have to match the answers that you marked with the answers that are given in the official answer key.

Hope it helps.

Good luck.