How CBSE Class 12 board marks are worked out

How does a written exam mark become the score on a CBSE Class 12 marksheet, and can practical marks make up for a weak theory paper? The answer depends on the subject and on separate rules for passing. A subject total, its grade and an admissions percentage each tell you something different.

The subject details below come from CBSE's 2026 to 2027 curriculum files. The English Core, Economics and Accountancy files still carry some 2025 to 26 headings. Passing rules come from the Examination Bye-Laws and later amendments. The supplementary and result-review instructions cover the 2026 arrangements. For 2027, check that cycle's instructions and timetable.

Start with the subject's split

The split between theory and practical marks varies by subject in Class 12:

• English Core has an 80-mark written paper and 20 internal marks: 5 for listening, 5 for speaking and 10 for project work.
• Mathematics has 80 written marks and 20 internal marks. Periodic tests contribute 10, using the best two of three tests; mathematics activities contribute 10.
• Physics, Chemistry and Biology each have 70 theory marks and 30 practical marks.
• Economics has 80 theory marks and a 20-mark project. Accountancy has 80 theory marks and 20 project or practical marks, depending on the option.
• Computer Science has 70 theory marks and 30 practical marks. Painting has 30 theory marks and 70 practical marks.

Add the marks earned in each component. For a worked example, 50 out of 70 in Physics theory plus 25 out of 30 in practical gives 75 out of 100. Use the marks rather than averaging the component percentages, since the components carry different weights. Practical marks are already part of the subject total.

What the practical or internal component contains

Practical or internal marks can cover several tasks. Physics assigns 14 marks to two experiments, 5 to the practical record, 3 to an activity, 3 to the investigatory project and 5 to viva. Chemistry and Biology also divide practical marks among specified tasks, records and oral assessment.

Computer Science divides its 30 practical marks into 8 for the Python programming lab test, 4 for SQL queries, 7 for the report file, 8 for the project and 3 for viva. The project is just one part of this assessment.

In Accountancy's Financial Statement Analysis option, the project file carries 12 marks and viva 8. The Computerised Accounting option instead has a practical file worth 12 and viva worth 8. Students submit the work for their chosen option. English Core assesses listening, speaking and project work, which differ from a laboratory practical.

Passing involves more than adding up

To pass Class 12, you need at least 33 per cent in each of the five external-examination subjects, with replacement allowed under certain conditions. An overall average of 33 per cent is insufficient. In a subject with practical work, you need 33 per cent in theory and practical separately, as well as 33 per cent in the combined total. You must meet the theory minimum even if your practical marks are strong.

For internal assessment, check the subject's own scheme for any separate minimum. The practical rule does not automatically apply to every internal component. Also check how the minimum for each component is rounded to a whole mark; the percentage rule alone leaves this open.

The separate compulsory internal-assessment areas are Health and Physical Education, Work Experience and General Studies. The curriculum also says Work Experience is included within Health and Physical Education. The bye-laws require a grade above E in each unless you are exempted. These grades are separate from the numerical internal or project marks within subjects.

Which subjects count, and who calculates a percentage?

Under the current scheme, your main subjects are the first five in the order entered in the online registration system or listed on the marksheet. A sixth subject can replace a failed main subject only if the scheme's conditions are met. These include keeping Hindi or English among the main five. Simply taking your five highest scores does not determine whether you pass.

CBSE reports subject marks separately, without an aggregate score or percentage. If you take six or seven subjects and pass all of them, the curriculum says the college or institution's admission rules determine how to calculate your percentage. A percentage calculated by you or your school is separate from the subject marks CBSE awards. Before using a best-five calculation for admission, check what that institution requires.

Why a grade is different from a mark

Class 12 grades depend on how passing candidates rank in each subject. The highest eighth receive A1, followed by A2, B1, B2, C1, C2, D1 and D2 for successive eighths. E means Essential Repeat. Ties can change the sizes of the groups.

CBSE's notification of 16 May 2024 says this eight-group grading applies where more than 500 candidates pass the subject. Where fewer than 500 pass, grading follows the pattern and distribution of other similar subjects. The same marks in two subjects can receive different grades. A1 is not a fixed band of 91 to 100. Relative grading leaves the numerical mark unchanged.

Compartment and supplementary examinations

CBSE renamed the Compartment Examination the Supplementary Examination from 2023. The name change left eligibility unchanged. A compartment result and a Pass result followed by an improvement application are separate cases.

In the 2026 cycle, regular Class 12 compartment candidates could apply in one subject. Those who took six subjects and were placed in compartment in two could choose either one. Candidates declared Pass could apply for improvement in one subject from the permitted list of subjects whose supplementary examinations were held.

The 30 June 2026 circular allows candidates placed in compartment in the main examination a maximum of three chances. For the relevant 2025 cohort, these were the 2025 supplementary examination, the 2026 main examination and the 2026 supplementary examination. The last application was as a private candidate.

The practical instructions of 22 July 2026 set out two cases: RP, Repeat in Practical, and RB, Repeat in Theory and Practical Both. RP candidates repeat only practical and keep their theory marks. RB candidates repeat both. The RP rule follows clause 42(iv) of the Examination Bye-Laws as amended on 28 February 2022. That amendment replaced older wording that required candidates who failed practical to repeat theory too.

How answers earn marks

CBSE introduced on-screen marking for Class 12 in 2026. Written answer books are scanned. Human examiners assess them using the marking scheme and enter marks for each question. Examiners decide the credit each answer deserves; the system adds the marks.

The 2026 to 2027 English Core sample scheme accepts correct answers in students' own words. Students can express its suggested points without memorising one wording. For notice writing, it gives four marks: 1 for format, 2 for content and 1 for spelling and grammar. Its format criteria allow half a mark when one or two specified aspects are missing. This shows partial credit for that task, rather than a general right to step marks.

What to check in practice

Read each subject's syllabus alongside its sample marking scheme. The syllabus explains the components; the scheme shows how answers earn marks. Check both component results and the subject total to see whether you have passed. For admission applications, use the institution's percentage rule.

If a result seems wrong, CBSE's June 2026 guidance sets out separate processes for verifying issues such as missing scanned pages and re-evaluating specified questions. In the 2026 process, students could apply for re-evaluation of one or more questions in a subject once they had obtained its scanned answer book. A review can raise, lower or leave marks unchanged. Check the instructions for your examination cycle before applying.