Class Attendance Calculator

Written byOleh Soloninupdated 25 September 2026

Classes in the course

Held so far

Attended of those

Required attendance, %

Result

Verdict10 more absences are possible
Current attendance, %88.89%
Can still miss10
Must still attend5
Classes remaining15
Final at full attendance, %91.67%
How it was worked out
75% of 60 classes means 45 attendances; 40 are already in, so 5 more are needed out of the 15 left

The margin runs out faster than it looks

Works out current attendance and how many more classes can be missed before the threshold is lost.

The threshold applies to the whole course, not to the part already taught. If a course runs 60 classes at a 75 percent requirement, 45 attendances are needed; once 40 of them are banked, five of the remaining fifteen classes are compulsory and ten can still be missed.

Current attendance can look comfortable while that is happening: 40 out of 45 is 88.9 percent. The trap is that the allowance is not measured against the percentage but against the absolute number of attendances the threshold demands.

The calculator shows both at once — where you stand now, and how many more classes you can afford to miss. When the threshold has become unreachable it says so instead of printing a number.

How to use

Enter the total number of classes on the course.
Enter how many have been held and how many of those you attended.
Set the attendance requirement as a percentage.
Read off the current percentage, the absences left and the classes still compulsory.

How the allowance moves with the threshold

Every row is a calculator run on a 60-class course with 45 held and 40 attended. Current attendance is the same in all of them — 88.89 percent — while the allowance changes fifteenfold.

Calculator runs with 60 classes, 45 held and 40 attended.
Requirement	Attendances needed	Still compulsory	Can still miss	Classes left
50%	30	0	15	15
60%	36	0	15	15
70%	42	2	13	15
75%	45	5	10	15
80%	48	8	7	15
90%	54	14	1	15

When the threshold slips out of reach

It happens when more attendances are still required than there are classes left. A 60-class course at 75 percent needs 45 attendances; if only twenty have been banked by the fiftieth class, 25 more are needed and ten remain — so the calculator prints "no longer reachable" rather than a count.

The consequence is straightforward: the earlier you run the numbers, the more leverage you have. Early in a course a missed class costs one from the allowance; late on it can cost the whole entitlement to sit the exam.

What this calculator shows

Current attendance as a percentage
How many classes can still be missed and how many must be attended
The final figure if nothing more is missed

What to keep in mind

The threshold is measured against the total number of classes in the course, as most regulations define it.
Excused absences are handled differently by different institutions and are not modelled.

FAQs

How many classes can I miss at a 75 percent requirement?

It depends on what you have missed already. A 60-class course needs 45 attendances; with 40 banked, five of the fifteen classes left are compulsory, so ten absences remain.

Why is the allowance only ten at 88.9 percent?

Because the threshold counts against the whole course rather than the part taught so far. The current percentage looks healthy, but the requirement is an absolute number — 45 attendances out of 60, however they fall.

What does "no longer reachable" mean?

That more attendances are required than there are classes left. No amount of discipline from here closes the gap, so it becomes a conversation with the course leader rather than an arithmetic problem.

Do authorised absences count?

That is for your institution to say, not the calculator. Some institutions count an authorised absence as attended, others take it out of the total or treat it separately, so apply your own rule rather than adding it to attendance by default.

Where is the attendance requirement written down?

In the course handbook or the assessment regulations. There is no single figure across institutions, which is exactly why it is an input here.

What if classes have different lengths?

Count in hours rather than sessions: enter total hours on the course, hours held and hours attended. The arithmetic is unchanged.

What does the perfect-attendance figure show?

Where the course would finish if you missed nothing more. With 40 attended out of 60 and fifteen classes left, that ceiling is 91.67 percent.

Worked example

A 60-class course

Input: 60 classes total, 45 held, 40 attended, 75% required

Output: 88.89% now, 10 absences left, 5 classes still compulsory

Note: Attending everything that remains would finish the course at 91.67 percent.

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