Percentile score is generally used in academics where rank or actual performance of a student is indicated among total batch of students. It is the measure of a score which tells what percentage of a data set is below that score. How to calculate percentile is described here with example. Suppose a class 10 student got 90 out of 100 in a subject and there are 40 students in his class. If there are 30 students who obtain less than 90 in same subject then his percentile will be (30/40)*100=75. Therefore for percentile calculation the score is not important but how many people is below that score is important.
Formula to calculate Percentile is shown below.
![\[Percentile=\frac{((B +0.5 . S) .100)}{ N} \]](https://how-to-calculate.com/wp-content/ql-cache/quicklatex.com-16f00d5d3fb2c2634ff3a70f9ea99f7b_l3.png "Rendered by QuickLaTeX.com")
Where ,
B= Number of students whose score is below yours
S= Numbers of students having same score.
N=Total no. of students in the batch
How to calculate Percentile rank
Percentile also denotes the rank of any score, meaning higher is the percentile better is the rank or score. For example Pth percentile of a student denotes that P% students have lower rank than his. If there are total N students in that batch than, the rank of that student will be (100-P)*N/100
Therefore Percentile Rank Formula will be.
![\[ Rank= \frac{(100-P) .N}{100} \]](https://how-to-calculate.com/wp-content/ql-cache/quicklatex.com-cf87cddea30d9ec9a4c4a879ad186099_l3.png "Rendered by QuickLaTeX.com")
Suppose a student got 90.2 percentile in CAT exam and total no. of student who wrote the exam is 40000 than, the rank of student will be
Rank= (100-90.2)*40000/100=3920th
It also means (40000-3920) = 36080 students got lower marks than him.
What is 100 percentile score in CAT exam?
100 percentile in CAT exam means 99.995 percentile. No one can get 100 percentile, even the percentile of highest scorer will be (N-1).100/N as there will be (N-1) students below his marks. Due to higher numbers of applicants (N) the few top scorer gets more than 99.995 percentile therefore are called 100 percentile scorers. Whereas 99.99. Percentile means above 99.985 and below 99.995.
