How to Use This Tool
Enter how many sessions you have attended, how many have been held, and how many are left. The useful outputs are the last two: whether the target is still reachable, and how much slack you have.
Why recovery is slow
Attendance is a fraction, and attending a session adds one to both the top and the bottom. That means each extra attendance moves the percentage less than the previous one, and the effect is strongest when you are furthest behind.
Starting from 30 of 45 — 66.7% — and attending everything from here, the requirement to reach 75% is:
(30 + n) ÷ (45 + n) ≥ 0.75, which rearranges to n ≥ 15.
Fifteen consecutive sessions with no further absence, to recover from fifteen misses. Miss one more during that run and the count starts climbing again.
The unreachable case
If fewer sessions remain than the recovery needs, the target is arithmetically impossible however perfectly you behave. With only ten left, the best achievable is (30 + 10) ÷ (45 + 10) = 72.7% — below a 75% requirement, permanently.
Nothing announces this. It is worth checking early precisely because the moment it becomes impossible passes silently, and the useful conversation with a tutor or manager is the one that happens before that point rather than after.
How many more you can afford
The other direction is usually the practical question. Given the sessions remaining, the number you can still miss is:
allowance = (attended + remaining) − target × (held + remaining)
With 30 of 45, 20 remaining and a 75% target: (30 + 20) − 0.75 × 65 = 1.25, so one more absence. Two would put you below.
Notice how sensitive that is. Ten more remaining sessions instead of twenty turns an allowance of one into an impossibility, because the extra sessions are the only thing that lets the fraction move.
What the number does not know
- Excused absences. Many institutions exclude authorised absences from the denominator entirely rather than counting them as attended, which changes the arithmetic completely. Check which applies before relying on any figure.
- Partial attendance. Arriving late or leaving early may count as present, absent, or half, depending on local policy.
- Per-module rules. A requirement is often per course rather than overall, so a good average can hide one module that is failing.
- What the threshold does. Below it the consequence might be a warning, a barred examination, or a visa condition. Those are not the same thing, and the arithmetic is identical for all of them.
Use this to see the shape of the problem, and take the actual rules from whoever enforces them.
