The Central Board of Secondary Education (CBSE) has outlined the Class 12 Computer Science marks distribution for the 2026–27 academic session, providing students with a clear picture of the weightage assigned to each unit.
According to the syllabus for Computer Science (Subject Code 083), the examination carries 100 marks, divided into 70 marks for theory and 30 marks for practical assessment.
The distribution shows that Computational Thinking and Programming – 2 carries the highest weightage, accounting for 40 of the 70 theory marks. However, students should not overlook Database Management, which contributes another 20 marks.
The official syllabus specifies the following weightage for the theory examination:
Unit 1: Computational Thinking and Programming – 2: 40 marks
Unit 2: Computer Networks: 10 marks
Unit 3: Database Management: 20 marks
Total theory marks: 70
Practical assessment: 30 marks
Overall total: 100 marks
In percentage terms, programming accounts for approximately 57.1% of the theory paper, followed by Database Management at 28.6% and Computer Networks at 14.3%.
With 40 marks, Computational Thinking and Programming – Unit 2 is the most important in terms of marks allocation.
Students are expected to prepare the following topics:
Python functions, parameters, arguments and variable scope
Exception handling using try-except-finally
Text file operations, including reading, writing and appending data
Binary file handling using the pickle module
CSV file operations
Stack implementation using Python lists
Revision of Class 11 Python concepts
Preparation strategy: Students should practise writing complete programs rather than memorising definitions alone. File handling, functions and stack operations deserve regular revision.
Computer Networks carries 10 marks, making it the lowest-weightage theory unit.
The syllabus includes network evolution, data communication, transmission media, network devices, topologies, protocols and web services.
Students should understand differences between network types, identify the functions of networking devices and revise commonly used protocols such as HTTP, HTTPS, FTP, SMTP and TCP/IP.
Although the unit carries fewer marks, its relatively compact syllabus makes it an important area for systematic revision.
Database Management accounts for 20 marks, making it the second-highest-weightage unit.
Important topics include:
Relational database concepts and keys
SQL commands and constraints
SELECT queries, filtering and sorting
Aggregate functions, GROUP BY and HAVING
Joins involving multiple tables
Python–SQL connectivity
Students should practise SQL queries involving different conditions and understand how Python applications interact with databases.
The 30-mark practical assessment is divided into four components:
Python programming lab test: 8 marks
SQL queries lab test: 4 marks
Practical report file: 7 marks
Project: 8 marks
Viva voce: 3 marks
Total: 30 marks
The practical file must include at least 15 Python programs, five sets of SQL queries and four Python–SQL connectivity programs.
For the Python lab test, the assessment gives 60% weightage to program logic, 20% to documentation and 20% to code quality.
Based on the official marks distribution, Python programming should receive the largest share of preparation time, followed by SQL and database concepts.
However, unit-wise marks should not be confused with chapter-wise weightage. CBSE has specified marks for the three broad units but has not assigned separate marks to individual topics such as functions, file handling or SQL joins in the uploaded syllabus.
Students should therefore cover the complete syllabus, practise programming questions regularly and prepare their practical files and projects well before the examination.