Normalisation of Marks: How Multi-Shift Exam Scores Are Made Comparable

Large recruitment exams cannot be held at one sitting. Lakhs of candidates sit the same computer-based test across days and shifts, each shift with a different question paper. However carefully those papers are set, one will turn out harder than another — and a candidate who drew the harder shift would be ranked lower for no fault of their own. Normalisation is the adjustment that corrects for this before the merit list is drawn up.

To see which recruitments are open to you now, start from 12th pass or jobs for graduates. The two exams this guide draws on are the SSC CGL and the RRB NTPC.

What Normalisation Does — and Does Not Do

Normalisation converts each candidate's raw marks into a normalised score that can be compared across shifts. The Railway Recruitment Boards put the point bluntly in their published explanation: it "is a scientific and statistical process. It is not a process of awarding grace marks."

So normalisation does not add marks to everyone, and it does not reward a whole shift. It places each candidate relative to the people who sat the same paper, and then puts all shifts on one scale. Depending on how hard your shift was, your normalised score can come out higher or lower than your raw score — or, in the reference shift, the same.

It also comes after the answer key. Your raw score is fixed first, once objections to the provisional answer key are settled; normalisation works on that final raw score.

How SSC Describes Its Method

The Staff Selection Commission's notice for the Combined Graduate Level Examination 2025 states that marks from a computer-based exam held in multiple shifts "will be normalized by using the procedure published by the Commission vide Notice dated 02-06-2025 and such normalized scores will be used to determine final merit and cut-off marks."

That June 2025 procedure is percentile-based. Instead of adjusting marks by each shift's average, it places every candidate by where they rank within their own shift, and treats candidates at the same percentile position in different shifts as equivalent — a candidate who scored better than 80% of their shift is matched with candidates who scored better than 80% of theirs. Your rank among the people who sat your paper is what carries across.

How the Railway Recruitment Boards Describe Theirs

The RRBs publish their method in each recruitment, and have revised it over the years, so the clause in your own Centralised Employment Notice is the one that applies. Their published explanation for an earlier recruitment (CEN 01/2018) shows the logic clearly.

• One shift is chosen as the base session: the shift with the highest average raw marks, provided its number of candidates was at least 70% of the average across all shifts.
• Every other shift's marks are rescaled to the base session's average and spread, using the formula the RRBs published: Xn = (S2/S1)(X − Xav) + Yav, where X is your raw score, Xav and S1 are your shift's average and standard deviation, and Yav and S2 are the base session's.
• In the base session itself, normalised marks equal raw marks.

The same document shows how a raw score is first worked out when questions are dropped. With 100 questions, 2 ignored as wrong, 54 correct and 6 wrong, the net score is 54 − 2 = 52, and the score out of 100 is (52 ÷ 98) × 100 = 53.06. Dropped questions are taken out of the paper rather than given to everyone.

That formula belongs to that recruitment. The RRBs revise the method between recruitments, so read the normalisation clause of the CEN you applied under rather than assuming this one applies.

Percentile Is Not Percentage

A percentile is not the share of marks you scored. If you are at the 80th percentile of your shift, you scored as well as or better than 80% of the candidates in it — whether that took 40% of the marks in a hard paper or 70% in an easy one. Percentile-based methods compare positions, not marks.

What It Means for You

• Cut-offs are on normalised scores. SSC says so in terms. A raw score you counted from the answer key is not directly comparable with a published cut-off.
• Your normalised score depends on everyone else. It turns on how the rest of your shift performed, which no candidate can see. A calculator can estimate it; only the recruiter's scorecard is final.
• A "hard shift" is not a disadvantage in itself. If everyone found it hard, your position among them is what counts.
• The decimals are the tell. Published scores such as 457.05141 in SSC's CGL 2024 result are normalised scores, not raw marks.

The cut-off guide explains how those normalised scores become cut-offs, and the merit list guide how they become a ranking. To work out your raw score from a marking scheme first, use the exam score calculator.

Frequently Asked Questions

Is normalisation the same as grace marks?

No. The RRBs describe it as a statistical process that is "not a process of awarding grace marks". It adjusts for differences in paper difficulty between shifts; it does not add marks across the board.

Can my normalised score be lower than my raw score?

Yes. If your shift's paper was easier than the reference, your raw marks are adjusted down to be comparable with candidates who sat harder papers — and up if your shift was harder.

Are cut-offs based on raw or normalised marks?

On normalised marks, where an exam ran in several shifts. SSC's notices state that normalised scores determine final merit and cut-off marks.

Can I calculate my exact normalised score?

Not exactly. It depends on the whole distribution of scores in your shift and the others, which only the recruiter holds. Estimates are possible; the scorecard is final.

What happens to questions that were dropped from the answer key?

In the RRB method described above, a dropped question is removed from the paper and your score is worked out over the remaining questions — not awarded to everyone.

In Summary

Normalisation makes scores from different shifts comparable, so that drawing a harder paper does not cost you a rank. It is not grace marks. SSC now matches candidates by their percentile position within their own shift; the RRBs have used an average-and-spread formula against a base session and revise their method between recruitments. Either way, cut-offs and merit run on normalised scores, and the method that applies is the one in your own notice.

Sources

• Staff Selection Commission, CGL Examination 2025 notice (21 May 2026), para 13.2 — normalisation under the Notice of 2 June 2025
• Railway Recruitment Boards, "Normalization of Marks in CBT2 under CEN 01/2018: A Scientific and Statistical Process"
• Staff Selection Commission, CGL 2024 final result write-up — published normalised scores