Attendance Calculator
Find how many classes you can skip, or must attend, to keep 75% attendance.
How it works
Choose a mode, enter the classes attended and held, then set the required percentage. The result updates as you type and shows what your attendance would be after the skips or attended classes it recommends.
Skippable = floor((100 × attended − required% × held) ÷ required%)
Must attend = ceil((required% × held − 100 × attended) ÷ (100 − required%))Example
With 50 of 70 classes attended (71.43%) and a 75% requirement, you must attend 10 classes in a row: 60 of 80 is exactly 75%, while 9 gives 59 of 79 = 74.68%. With 42 of 50 (84%), you can skip 6 classes: 42 of 56 is exactly 75%.
Common mistakes
- Forgetting that a skipped class still counts as held. Skipping adds to the total, so attendance falls even though your attended count is unchanged.
- Rounding the percentage up. 74.6% is below 75%, even if it looks close.
- Assuming a few classes can recover a high requirement. The nearer the requirement is to 100%, the more classes in a row you need.
About this calculator
Enter the classes you have attended, the classes held so far and the attendance your institution requires (75% is filled in). In skip mode it tells you how many future classes you can miss and still stay at or above the requirement. In attend mode it tells you how many classes in a row you must attend, with no absences, to reach the target.
Everything is counted in whole classes, and the percentage boundary is exact: 75 of 100 is exactly 75%, so it passes, while 74.99% does not display as 75%. Future classes are treated as equal. Rules such as medical or other condonation are not modelled, so check your own institution's policy.
Frequently asked questions
How many classes can I skip and still have 75% attendance?
Skip as many as keep attended ÷ (held + skipped) at or above 0.75. With 42 of 50 classes attended you can skip 6, because 42 of 56 is exactly 75%. A 7th skip would drop you to 73.68%.
How many classes do I need to attend to reach 75%?
Attending y classes in a row raises both counts by y, so you need (attended + y) ÷ (held + y) ≥ 0.75. With 50 of 70, y = 10 gives 60 of 80 = 75%. The result is rounded up to a whole class.
Why can't I reach 100%?
Once a class has been missed, attended is permanently below held, so attendance can approach 100% but never equal it again. The calculator reports that a 100% target is not possible instead of showing a number.
Does skipping a class lower attendance even if I attended every other one?
Yes. A skipped class that is still held adds one to the total and nothing to your attended count, so the percentage drops.
Does this handle holidays, medical leave or condonation?
No. It only does the arithmetic on the counts you enter. If your institution excuses some absences, enter your attended and held counts after applying those rules.