CBSE Class 12 Practical Exam 2027: Marks, Examiners and Rules

The CBSE Class 12 practical exam for 2027 will be held in your own school, marked by an external examiner whom CBSE appoints and an internal examiner from your school. The practical or project is worth 30 marks in Physics, Chemistry, Biology and Computer Science, and 20 marks in Accountancy, Business Studies, Economics, History and Political Science. CBSE has not issued the 2026-27 practical schedule yet. In the last two sessions, regular schools held practicals from 1 January to 14 February.

Much of the practical mark rests on work you finish before the day: the record, the project and how well you can talk about them in the viva.

TL;DR

• CBSE appoints the external examiner for Class 12 practical and project subjects. Your school cannot replace that examiner.
• Maths has 20 marks of internal assessment, from periodic tests and activities that your school runs.
• In Computer Science, 18 of the 30 practical marks go to the report file, project and viva.
• In Accountancy, Business Studies and Economics, the viva alone carries 8 of the 20 project marks.
• Marks are uploaded on the day and CBSE allows no correction after that.

When are CBSE Class 12 practicals held for 2026-27?

As of 31 October 2026, cbse.gov.in shows no practical notice for 2026-27. So I can only give you the pattern from CBSE's last two guidelines documents, which match.

• 2024-25: winter-bound schools 5 November to 5 December 2024 (31 days), regular schools 1 January to 14 February 2025 (45 days).
• 2025-26: winter-bound schools 6 November to 6 December 2025 (31 days), regular schools 1 January to 14 February 2026 (45 days).

CBSE's Circular No. 04/2026 of 10 February 2026 said about 30% of schools had still not completed the conduct or upload of marks, four days before the deadline. Your school picks your day inside the window. For theory paper dates, see our CBSE date sheet 2027 post.

If the pattern holds, regular-school practicals will fall between 1 January and 14 February 2027. Treat that as a pattern until CBSE confirms it.

Which Class 12 subjects have a practical, a project or internal assessment?

I counted the subject list in CBSE's 2026-27 Senior Secondary curriculum. Its 39 academic electives split like this:

• 13 are 70 theory and 30 practical, including Physics, Chemistry, Biology, Computer Science, Informatics Practices, Geography, Psychology and Physical Education.
• Accountancy, Business Studies and Economics are 80 theory and 20 project.
• 6 are 80 theory and 20 project or internal assessment: History, Political Science, Sociology, Mathematics, Applied Mathematics and Legal Studies.
• 16 music, dance and fine arts subjects have only 30 marks of theory, and Knowledge Tradition and Practices of India is 70 and 30.

All 39 languages, English Core included, are 80 theory and 20 internal assessment. The point that matters is who marks you. CBSE's guidelines send an external examiner for practical and project assessments in Class 12, while Maths internal assessment comes from periodic tests and activities that your school conducts.

Practical and project subjects get a Board-appointed examiner. Maths internal assessment is marked by your school.

How are the practical marks split in each subject?

The breakdown for the main subjects, from each 2026-27 curriculum document:

• Physics (70 + 30): two experiments 7 + 7, record 5, one activity 3, investigatory project 3, viva 5.
• Chemistry (70 + 30): volumetric analysis 8, salt analysis 8, content-based experiment 6, project 4, class record and viva 4.
• Biology (70 + 30): major experiment 5, minor experiment 4, slide preparation 5, spotting 7, record and viva 4, project with viva 5.
• Computer Science (70 + 30): lab test 12 (Python 8, SQL 4), report file 7, project 8, viva 3.
• Informatics Practices (70 + 30): Pandas and Matplotlib 8, SQL 7, practical file 5, project 5, viva 5.
• Geography (70 + 30): written test 25, practical file 2, viva 3.
• Psychology (70 + 30): two psychological tests 15, file and case profile 10, viva 5.
• Physical Education (70 + 30): fitness test 6, one sport 7, yogic practices 7, record file 5, viva 5.
• Accountancy, Business Studies and Economics (80 + 20): project 12, viva 8.
• History (80 + 20): project stages 16, viva 4. Political Science: project 10, viva 10. Sociology: project 15, viva 5.
• English Core (internal): listening 5, speaking 5, project 5, viva 5. Mathematics (internal): periodic tests 10, activities 10.

Source: CBSE Class XII curriculum 2026-27 subject PDFs on cbseacademic.nic.in, compiled by Gradehunt on 31 October 2026.

Every science practical has a record and a viva, and every 20-mark project ends in a viva.

How much of the practical is decided before the exam day?

I split each scheme in two. The first part is the task you perform on the day: experiments, a lab test, spotting, a written test or a fitness test. The second is the record, file, project and viva, which rest on work done in the months before.

• Computer Science: 12 on the day, 18 for file, project and viva.
• Informatics Practices and Psychology: 15 and 15.
• Physics: 17 and 13. Physical Education: 20 and 10.
• Biology: 21 and 9. Chemistry: 22 and 8.
• Geography: 25 and 5.

A Computer Science student with a finished report file and a working project has 15 marks resting on work already done before the lab test starts. A Geography student has no such cushion, because 25 marks come from a written test on the day. In the project subjects the viva is heavy: 10 of 20 in Political Science, and 8 of 20 in the three commerce subjects.

Method: Gradehunt added the marks heads in each 2026-27 evaluation scheme. Chemistry and Biology print record and viva as one head, so that head sits in the second part.

Record, project and viva carry 60% of the practical in Computer Science and only a sixth in Geography.

Who marks the practical, and how does the external examiner work?

These rules come from CBSE's guidelines and SOPs for the 2025-26 practicals. The 2026-27 version is not out yet.

Before and during the exam

CBSE appoints the external examiner and may send an observer. Your school appoints the internal examiner. The external examiner checks the lab at least a day before. Students are examined in groups of up to 30, and both examiners agree on which experiment you get. Both can ask viva questions, which should relate to your project or the practical in hand. A geotagged group photo with both examiners is taken in the lab.

Marking and upload

If the two examiners still differ by one or two marks after discussion, you get the average. A fractional total goes up to the next whole number, so 25.5 becomes 26. Marks are uploaded the same day and cannot be corrected later. Schools are told not to disclose them to students.

Two examiners mark you together, and the marks go online that day.

What happens if you miss the practical?

In 2025-26, a student absent on the day was marked "Re-scheduled" and examined later, but only inside the notified window. CBSE said it would not entertain requests beyond that schedule. If you fall ill in early February, tell your school the same day so it can fit you in before 14 February.

A missed practical can be retaken only within CBSE's window.

How should you prepare for the Class 12 practical?

1. Finish your record or file by mid-December and get it signed by your teacher.
2. Write a one-page summary of your project: aim, method, result and one limitation. CBSE wants viva questions to come from the project or the practical, so this page is your viva revision.
3. Do every experiment on your school's list once with your own hands and note the readings.
4. Practise the written parts: 25 marks in Geography, and Python and SQL in Computer Science and IP.
5. Keep theory revision going in January. You need 33% in theory and in the practical separately, as our CBSE passing marks post explains.

Get the file and project done early, then give January to theory.

The practical happens in your school, but the 70 or 80 theory marks decide most of your result. The Gradehunt CBSE Class 12 test series gives you full papers in the board pattern. You write by hand, upload, and subject experts return your answer sheet within 48 hours with step-wise marks and comments. Your first paper is checked free.