When 75% is the published bar
Plenty of undergraduate handbooks mention 75% as a typical minimum. That does not mean every university, faculty, or elective uses it. Engineering departments sometimes sit at 75% while a clinical module next door uses a higher figure. Treat 75% as a common default, then confirm the number printed for your course.
This page opens the calculator with 75% already selected. You can still switch to 80% or 85% if your offer letter says otherwise. The math does not change: present sessions divided by held sessions, then compared with 0.75.
A 75% example with labs, not lectures
Imagine a chemistry paper with 16 lectures and 8 labs already held (24 sessions). You missed two lectures and one lab, so you have 21/24 = 87.5% so far. That looks comfortable until you notice there are 8 labs left and you tend to skip the Friday slot. If those 8 labs all run, the new total is 32. Seventy-five percent of 32 is 24. You already have 21, so you can miss 5 of the remaining 8 only if you attend 3. Skip every Friday and you land at 21/32 = 65.6% — below 75% even though you started the month “safe”.
Another 75% snapshot: mid-semester theory paper
You have 33 of 40 lectures. That is 82.5%. Twelve lectures remain. Final total 52; 75% of 52 is 39. You need 39 present and already have 33, so six more must be attended and you can miss six. Students often hear “I can miss 25% of the semester” and skip 10 of those 12. The 25% slogan only holds if you have not already used absences. Here the remaining budget is six, not thirteen (25% of 52).
Medical leave and 75% rules
Some colleges let documented illness sit outside the percentage, or they run a condonation window where a fee plus a medical certificate buys a few percent. Others fold every absence into the same ratio. This tool cannot apply condonation; it only shows the raw ratio. If you expect a medical adjustment, calculate twice: once with official held classes, and once with the sessions your office says will be excluded.
If you are already under 75%, switch to “How Many Must I Attend?”. Consecutive future classes raise both the numerator and the denominator. From 30/50 (60%) you need 30 more consecutive sessions to reach 75% on that formula — which only works if 30 sessions still exist. Read what happens if attendance is below 75% for process, not just arithmetic, and use how many classes can I miss when you still have a buffer.