Hello

The number of people whose score is below you or the number of people you've scored better than out of total number of people appeared in examination is your percentile. So, here scores of other people matter as well in terms of evaluating performance.For example, 90th percentile, that means you scored better than 90% of people who took the test. 

Thank you!

Hi Candidate! It seems like you might written incomplete question. It is very difficult to predict percentile because nothing is mentioned in the question. So please do mention your qualifying exam in which you want to check percentile so that I can provide you enough information regarding it. Feel free to ask any doubt.

Thanks.