Calculation of percentile, normalization of marks and Composite score

Percentile

Difference between Percentage & Percentile & calculation of percentile:

Percentage: As you all know percentage is a number out of 100.Percentage marks = (Obtained marks / Total marks) ×100

Percentile:Percentile score of a candidate reflects the number of students who have scored below that student in his/her own Board ( CBSE, ICSE etc..)
Example:In a particular board 4000 candidates appeared in the examination.If a candidate obtained 70 % marks and 2000 students have scored below 70%, then the percentile of that student = (2000×100)/4000 = 50.0

Normalization of marks

Step 1:
Calculate percentile (P) of all the candidate of board XYZ who are eligible for the JEE (Main) exam, with reference to their board result.
For a Board XYZ
Total Number of the candidates appearing in board exam = 4000

Marks of candidates in Board Exam (m)	Number of candidates who scored below the candidate (m)	Percentile Calculation	Percentile (p1)
50%	1500	(1500/4000)×100	37.5
60%	1700	(1700/4000)×100	42.5
70%	2000	(2000/4000)×100	50.0
80%	2500	(2500/4000)×100	62.5
90%	3500	(3500/4000)×100	87.5

Step:2
In the same way calculate the percentile of all the candidates with reference to their JEE main score.
Let total number of the candidates appearing in JEE (Main) exam = 1000000

JEE(Main) Score (n)	Number of candidates below the candidate with JEE (Main) score (n)	Percentile Calculation	Percentile (p2)
75	500000	(500000/1000000)×100	50.0
100	600000	(600000/1000000)×100	60.0
150	700000	(700000/1000000)×100	70.0
200	800000	(800000/1000000)×100	80.0
250	900000	(900000/1000000)×100	90.0

 Step: 3
Use the value of percentile (P₁) calculated in step 1 (Table 1) and find out the same value of percentile in the table 2 (step 2). The corresponding JEE (Main) score would represent value of B₁.
In our example the percentile of candidate with 70% board marks was 50.
So in table 2, percentile 50.0 represents JEE (Main) score of 75. So, B₁ = 75. 

Step:4
Calculate the percentile of the candidates of the particular board (say XYZ ) who appeared in the JEE main with reference to their JEE main score.
Number of the candidates of board xyz appeared in JEE main = 4000

JEE(Main) Score (n)	Number of candidates below the candidate with JEE (Main) score (n)	Percentile Calculation	Percentile (p3)
25	1000	(1000/4000)×100	25.0
50	1500	(1500/4000)×100	37.5
100	2000	(2000/4000)×100	50.0
150	3000	(3000/4000)×100	75.0
200	3600	(3600/4000)×100	90.0

 Step: 5
Use the value of percentile (P₁) calculated in step 1 (Table 1) and find out the same value in the table 3 (step 4). The corresponding JEE (Main) score would represent value of B₂.
In our example the percentile of candidate with 70% board marks was 50.
So in table 3, percentile 50.0 represents JEE (Main) score of 100. So, B₂ = 100
Step: 6

B_final = 0.5× (B₁+B₂)
In our example:
B _final = 0.5× (75 + 100) = 87.5
For admission to CFTIs, it has been decided to use JEE Mains Marks (AO) and the normalized board marks(× B _final)  in 60:40 ratio.So,
Composite score for drawing the merit list (c ) = 0.6× AO + 0.4× B _final
In our example:
c  = 0.6× 75 + 0.4× 87.5 = 80.

For getting your estimated rank in IIT JEE you can use our  Rank Predictor

This post was published by Aditya Singhal, co-founder of askIITians.