CAT Normalisation Explained: Why Your Marks and Percentile Differ
CAT is held in multiple shifts on the same day, and no two shifts have identical questions or difficulty. Normalisation adjusts each candidate’s raw score to a common scale before ranking, so your percentile reflects your performance relative to everyone who took the exam — not just your own shift.
The three steps
- Raw score. Each correct answer scores +3, each wrong answer −1, calculated the same way for every candidate.
- Normalisation. Because slots vary in difficulty, IIM Indore adjusts raw scores to a scaled score that is comparable across all three shifts. The exact method is not published in full detail, but it is standard practice for any multi-shift exam.
- Percentile. Once every candidate has a scaled score, percentile is calculated as P = (1 − R/N) × 100, where R is your rank by scaled score and N is the total number of candidates who appeared.
This is why two candidates with the identical raw score in different slots can end up with different percentiles — their raw scores are adjusted differently going into the ranking. It is also why the marks-to-percentile table can only ever be an estimate before results are out: normalisation depends on the actual difficulty and performance spread of your specific slot.
What this means practically
- Don’t panic over a raw score that looks low if your slot was harder — normalisation exists precisely to correct for that.
- Don’t assume a high raw score guarantees a high percentile in an easier slot — the same correction can work against you.
- The only number that matters for admission is your final percentile, not your raw score.
Frequently asked questions
Why do CAT slots get normalised?
Because the exam runs in multiple shifts with different questions, and no two shifts have exactly the same difficulty. Normalisation puts every candidate on a comparable scale.
Does normalisation help or hurt my score?
Neither by design — it corrects for slot difficulty so your percentile reflects your relative performance, not the luck of an easy or hard shift.
What is the CAT percentile formula?
P = (1 − R/N) × 100, where R is your rank by normalised score and N is the total number of candidates who appeared for the exam.
Sources & methodology
General CAT exam-format explanation, not tied to a single source claim.