Percentage formula
Percentage = (marks obtained ÷ total marks) × 100. With several subjects, add the obtained marks together and add the paper totals together before dividing.
Example: 72/100 and 81/100 is 153/200 = 76.5%.
Grade bands
The label under the result uses a common school guide: 80% A+, 70% A, 60% B, 50% C, 40% D. Boards and universities publish their own scales, including CGPA conversions. Use the percentage itself on forms, and check the board gazette before you quote a grade.