How SSC normalises scores
When an exam runs in many shifts, SSC turns raw marks into normalised marks with an “equipercentile” method (notice of 02.06.2025, used by the CGL and CHSL 2026 notices). Your normalised score needs every shift’s results, which only SSC has; these steps show how it is worked out.
Step 1: your percentile in your shift
P = m ÷ N, where N is the number of candidates who appeared in your shift and m the number whose raw score is less than or equal to yours (to 8 decimals).
Step 2: the matching score in another shift
All shifts are merged by percentile. Where a shift has no candidate at exactly your percentile P, its score is interpolated between the nearest percentiles p1 and p2 (scores x1 and x2): X = x1 + (x2 − x1) ÷ (p2 − p1) × (P − p1).
Step 3: the normalised score
Z = (u1 + u2 + … + ut) ÷ t: the average of the raw scores at your percentile in each of the t shifts.
Source: SSC, “Normalization procedure for SSC exams from June 2025” (02.06.2025); explanatory note 10.09.2025. The example numbers above are made up to show the arithmetic.