How to use the attendance calculator
- Enter the total classes held so far (lectures, labs or working days — whatever your college counts).
- Enter how many of those you attended.
- Keep 75% or change it to your college's rule (some need 65%, 80% or 85%).
- Optional: add the classes left this semester to see how many of them you can still miss.
The answer updates as you type. It tells you your current attendance percentage and either how many classes you can bunk safely, or how many classes in a row you must attend to get back to the required percentage.
Attendance percentage formula
Attendance % = (Classes attended ÷ Classes held) × 100Example: you attended 42 of 60 classes → 42 ÷ 60 × 100 = 70%.
How many classes do I need to attend to reach 75%?
Classes needed = (0.75 × Held − Attended) ÷ (1 − 0.75)Round the answer up. With 42 of 60: (45 − 42) ÷ 0.25 = 12. Attend the next 12 classes without a break and you will be at 54 of 72 = 75%.
How many classes can I bunk and still keep 75%?
Classes you can miss = Attended ÷ 0.75 − HeldRound the answer down. With 54 of 60 (90%): 54 ÷ 0.75 − 60 = 12. You can miss the next 12 classes and still be at exactly 75% (54 of 72).
Quick table: classes to attend to reach 75%
| Classes held | Attended | Current % | Attend next (in a row) |
|---|---|---|---|
| 40 | 26 | 65.0% | 16 |
| 50 | 33 | 66.0% | 18 |
| 60 | 40 | 66.7% | 20 |
| 60 | 42 | 70.0% | 12 |
| 80 | 55 | 68.8% | 20 |
| 100 | 70 | 70.0% | 20 |
| 100 | 72 | 72.0% | 12 |
| 120 | 85 | 70.8% | 20 |
Why 75% attendance matters
Many Indian universities and colleges ask for a minimum of 75% attendance to sit for semester exams, and CBSE also expects 75% attendance in Classes 10 and 12. Falling short can mean a shortage notice, a condonation fee, or being stopped from writing exams. Checking your attendance every couple of weeks with this calculator lets you plan leave without risk.