Two questions come up every results season: "how many marks do I need to pass?" and "what will my percentage be?" Most students assume both are set by a fixed CBSE rulebook — a marks-to-grade table, a formula for percentage. Neither assumption is quite right. CBSE's own Examination Bye-Laws lay out something more specific, and in one case genuinely surprising.
The Actual Pass Criteria for Class 10 and Class 12
Under CBSE's Scheme of Examinations and Pass Criteria, the qualifying mark in every subject of the external (Board-conducted) exam is 33%. That figure works differently depending on whether the subject carries a practical component.
| Subject type | What you must clear | CBSE Bye-Law reference |
|---|---|---|
| Theory-only subject | 33% in that subject's external exam | Pass Criteria, para (iv) |
| Subject with practicals | 33% in theory AND 33% in practical, separately — plus 33% in the combined (theory + practical) aggregate | Pass Criteria, para (iv) |
| Internal assessment (every subject) | A grade higher than E — failing this withholds the result, though not for more than a year | Pass Criteria, para (i) |
Tip
The practical-subject rule catches students by surprise: scoring 90% in the practical does not cover for scoring 30% in theory. Each of the three thresholds — theory, practical, and their combined total — has to clear 33% independently.
Fail One Subject — What Happens Next
CBSE's Bye-Law 40.2 (Senior School Certificate Examination) is specific: a candidate who fails exactly one of the five subjects in the external exam, while clearing internal assessment in all subjects, is placed in compartment for that one subject only. The other four results stand. A compartment is not a second attempt at the whole year — it is a retest confined to the subject that fell short.
Why Two Students With the Same Marks Can Get Different Grades
CBSE reports both a numerical mark and a letter grade for every external subject. The letter grade is not read off a fixed marks band like 91–100 = A1. CBSE uses what it calls Relative Grading: within each subject, every candidate who passed is ranked, split into eight equal-sized groups, and graded by which group they land in.
| Rank position in the subject (passed candidates only) | Grade |
|---|---|
| Top 1/8th | A-1 |
| Next 1/8th | A-2 |
| Next 1/8th | B-1 |
| Next 1/8th | B-2 |
| Next 1/8th | C-1 |
| Next 1/8th | C-2 |
| Next 1/8th | D-1 |
| Next 1/8th | D-2 |
Because the cut-offs move with how the whole cohort performs in that specific subject in that specific year, an 85 in Chemistry and an 85 in Physics can land in different grade groups — the grade tells you where you stood relative to everyone who took that subject, not a fixed score threshold. (This method only applies where more than 500 candidates pass a subject nationally; smaller-cohort subjects borrow the distribution of a comparable subject.) Internal-assessment subjects are graded separately, on a simpler five-point A–E scale set by the school.
CGPA Exists Only for Class 10
A Cumulative Grade Point Average is issued only on the Class 10 marksheet — it is not combined across Class 9 and 10, and Class 12 has no CGPA at all (Class 12 results are subject-wise marks and grades only). CGPA is the average of the Grade Points across all subjects taken, excluding any additional sixth subject.
0 × CGPA
Indicative percentage from CGPA
CBSE calls this an "indicative" conversion, not an official one — which leads into the part of the pass-criteria rules that surprises the most families.
CBSE Does Not Calculate or Declare Your Percentage
This is stated plainly in CBSE's own November 2023 notice on the subject: Bye-Law 40.1(iii) specifies that "no overall division/distinction/aggregate shall be awarded," and CBSE confirms it "does not calculate/declare/inform percentage of marks" at all. If a student has offered more than five subjects, deciding which five count toward a "best of 5" percentage is explicitly left to the admitting institution or employer — not to CBSE.
- The percentage you see quoted in news reports or on results portals is a convention (typically the average of the best five subjects), not a figure CBSE itself certifies
- Different colleges can — and sometimes do — compute admission cut-off percentages differently from each other, using the same marksheet
- Your official record is the subject-wise marks and grades on the marksheet; the percentage is a downstream calculation, done by whoever needs it
Tip
For admissions or scholarship applications, don't assume the percentage you were told at school matches how a specific college will compute it. Keep the original subject-wise marksheet handy and check that institution's own stated method — the 33% pass mark and the CGPA-to-percentage formula are official; the overall "percentage" almost everyone quotes is not.