The Core Formula
The attendance percentage formula is straightforward — it measures what fraction of total scheduled classes you have attended, expressed as a percentage.
Derived Formulas
From the core formula, we can derive several other useful formulas for attendance management:
Minimum Classes to Attend (for any target %)
Example: For 75% with 80 total: ⌈80 × 0.75⌉ = ⌈60⌉ = 60 classes
Maximum Classes You Can Skip
Example: For 80 total: 80 − 60 = 20 classes you can miss
Classes Needed to Recover (from below 75%)
Example: If A=12, T=80: (0.75×80−12)/0.25 = 48/0.25 = 192 classes
Find Attended if % and Total are Known
Example: If 75% of 80 total: A = (75×80)/100 = 60 classes
Find Total if % and Attended are Known
Example: If 60 attended at 75%: T = (60×100)/75 = 80 total
Worked Examples
Let's apply the formulas to real scenarios:
Exactly at 75%. Cannot skip any more.
80% — can still skip 4 more classes.
Only 15% — needs 192 more consecutive classes.
Needs 100 more consecutive classes to reach 75%.
One class below minimum! Attend very next class.
90% — can skip 15 more and stay safe.
Try the Calculator
Use the live calculator below — enter your numbers and get an instant result with a progress bar and recovery plan.
Calculate Your Attendance Instantly
Free, real-time — check if you meet 75%, how many classes you can skip, and your recovery plan.