Add the marks obtained in all 12 subjects
Add the maximum marks of all 12 subjects
Use the formula: Percentage = (Total Obtained Marks ÷ Total Maximum Marks) × 100
If all 12 subjects are out of the same maximum marks, use: Percentage = (Sum of marks ÷ (12 × Maximum marks per subject)) × 100
Example: If you scored 840 out of 1200, then Percentage = (840 ÷ 1200) × 100
Percentage = 70%