CBSE Class 10 and 12 Board Exams 2027: Every Subject's Marks Split, and the Practical Dates to Note

On 5 November 2026 CBSE issued a circular every Class 10 and Class 12 parent should know exists: the subject-wise marks bifurcation for the 2027 board examinations. For every subject the board offers, it states how the 100 marks divide between the theory paper, the practical exam, project work and internal assessment. A second circular the same day fixes when practical exams and internal assessments will actually happen. Read together, they let you work out how much of your child's final mark will be decided months before they sit a single theory paper.

When practicals and internal assessment happen

The board has set two windows, depending on the school's calendar:

• Winter-bound schools: 9 November 2026 (Monday) to 19 December 2026 (Saturday), for both Class 10 and Class 12. These schools close through January, so their practicals, project assessments and internal assessments finish before the winter break.
• Regular session schools, in India and abroad: practical examinations, project and internal assessment begin 1 January 2027.

One caution on dates. The marks circular prints the regular-session window as "01.01.2027 to 13.12.2027" - we checked the printed document directly, and that closing date sits eleven months after the window opens, after the 2027 board exams themselves, so it reads as a typographical error. The companion circular issued the same day gives no closing date for regular schools. Until CBSE publishes a correction, treat 1 January 2027 as the firm start and confirm the closing date with your school. One more detail from the winter-bound circular worth knowing everywhere: for Class 10, internal assessment is conducted only once, so there is no second window if marks are missed or uploaded wrongly.

The one number to remember: every subject is out of 100

The circular's core rule is simple: the maximum for each subject is 100 marks, split between the theory examination and the assessed components (practical, project and internal assessment). What changes from subject to subject is the split. Most Class 10 subjects follow 80 marks for the board's theory paper plus 20 for internal assessment. In Class 12 the pattern shifts by stream: sciences and other practical subjects go 70-30, while commerce and humanities subjects with project work go 80-20.

Class 10: the split for the subjects most students take

Notice what is not there: Class 10's core subjects, Science included, have no separate practical exam. Their 20 marks come entirely from internal assessment within the school. Practical exams appear mainly in the skill subjects, which run a shorter, two-hour theory paper and an even 50-50 split - Computer Applications (165), Information Technology (402) and Data Science (419) all follow it. And for Class 10, the annexure shows no external examiner: practicals and internal assessment are conducted and marked inside the school.

Class 12: where the 30 practical marks live

In Class 12 the practical component carries real weight: for lab subjects, 30 of the 100 marks are settled in the practical exam, weeks or months before the theory paper. For these subjects the Board appoints an external examiner and supplies the practical answer-books.

Commerce and humanities students should note the pattern: Accountancy, Business Studies, Economics and Political Science trade the practical exam for a 20-mark project, assessed with an external examiner appointed by the Board. English Core and Mathematics keep the 80-20 split, with the 20 coming from internal assessment. Skill subjects in Class 12, such as Data Science (844), again use the 50-50 split with a two-hour theory paper.

Why CBSE published this list

The circular states its reason plainly: schools sometimes make mistakes while uploading practical, project and internal assessment marks, and those marks feed directly into your child's final result. The annexure - a subject-by-subject list covering both classes, with subject codes, the marks split, whether an external examiner is appointed, and even the type of answer book each theory paper will use - exists so schools upload against the correct pattern. For parents it doubles as a reference: you can check exactly how your child's school assessments convert into board marks, and how much of the 100 is effectively banked before exam season begins.

What to do now

1. 1If your child studies in a winter-bound school, practicals run 9 November to 19 December - ask the school for the subject-wise date sheet this week if you do not have it already.
2. 2Everywhere else, practicals and internal assessments begin 1 January 2027. Confirm your school's closing date, since the circular's printed end date appears to be a typo.
3. 3Look up your child's exact subjects in the annexure, especially any skill subject - the 50-50 split and two-hour theory paper change how revision time should be divided.
4. 4Treat internal assessment and practical marks as banked marks. Ask the school how those 20 or 30 marks are tracking well before the theory exams, while there is still time to act on the answer.