Attendance Calculator
Find your attendance percentage, how many classes you can still miss, and how many leaves are left in the semester.
Attendance percentage and leaves left
Add the total classes of the semester to see how many leaves you have left.
The formulas
Attendance % = (classes attended ÷ classes held) × 100.
If you are below the required percentage, the classes you must attend in a row are ceil((T × held − 100 × attended) ÷ (100 − T)), where T is the required percentage. If you are above it, the classes you can still miss in a row are floor((100 × attended − T × held) ÷ T).
Worked example
You attended 30 of 40 classes. That is 75%. With 75% required you can miss 0 more classes in a row. If you attended 28 of 40 (70%), you must attend 8 classes in a row: (75 × 40 − 100 × 28) ÷ 25 = 8, and 36 of 48 = 75%.
Leaves left in the semester
If the semester has S classes in total, you need ceil(T × S ÷ 100) attended classes by the end. The leaves you can still take are the remaining classes minus the ones you still need to attend.
Note
Your institute may count medical leave, rounding or lab hours differently. Use this as a planning tool and follow your own policy.
FAQ
How do I calculate attendance percentage?
Divide the classes you attended by the classes held and multiply by 100.
How many classes can I miss and still keep 75%?
Enter classes held and attended, and the required percentage. Calvo shows how many you can miss in a row. Add the semester total to see leaves left across the whole semester.
What if my attendance is already below the required percentage?
Calvo shows how many classes in a row you must attend to reach the target, and warns if it is impossible within the semester.
Does 75% mean exactly 75 or at least 75?
Most institutes need at least the required percentage. Some round up, so check your own policy.
Does it save my data?
No. Everything is calculated in your browser and nothing is stored.