A tracker built for the whole semester
Most attendance calculators answer one question and you move on. This page is different: save every subject once, and after each class tap +Present or +Absent on that subject — one tap, no retyping numbers, no confirmation dialog. Your data is saved automatically in this browser so it's ready the next time you open the page.
Each subject shows its own percentage and status, an overall roll-up across everything you're taking, and a "weakest subject" callout — because it's easy to track your overall number and still get blindsided by the one class you keep skipping.
How the numbers are calculated
Current percentage
pct = (attended / held) × 100
The raw percentage is shown to one decimal place. Colleges disagree on whether 74.6% should floor to 74% or round to 75% — this tracker never silently rounds a borderline value up for you; it flags it instead so you can check your institution's own policy.
Classes you can skip right now
skips = floor(attended / target% − held)
Shown for every subject you're on track in — the same "right now" figure the homepage calculator gives, with no total class count required.
Classes needed to recover
needed = ceil((target% × held − attended) / (1 − target%))
Shown when you're below target. Every class you attend adds to both the numerator and the denominator, so a naive guess that only grows the numerator understates how many you actually need — this formula accounts for that.
By-term-end forecast
maxPct = (attended + remaining) / totalClassesInSemester × 100
Only shown once you enter the Total Classes in Semester — projects where you'll land by the end of the term, capping the "right now" skip figure to what actually remains and flagging when target is mathematically out of reach.
Frequently Asked Questions (FAQ)
How is the Tracker different from the homepage calculator?
The homepage calculator answers a single one-off question: attended, held, and your target percentage in, an instant result out. The Tracker is built for the whole semester — you save every subject once, and each week you tap +Present or +Absent after class to keep every subject up to date, with an overall roll-up across all of them.
Is my data sent to a server?
No. The Tracker is 100% client-side, exactly like the homepage calculator. Your subjects, counts, and target are saved only in your browser's local storage. Nothing is ever uploaded, and there is no account or sign-in.
What happens if I clear my browser data or use private/incognito mode?
Local storage is tied to your browser profile, so clearing site data or browsing in a private window will remove (or never save) your tracker. In private mode the Tracker still works perfectly for that session — it just won't remember your subjects the next time you open the page. Use Copy Link before you close the tab if you want to keep a backup.
How do I share my tracker with a friend or move it to another device?
Tap Copy Link. It encodes your current subjects and target directly into the URL — nothing is uploaded anywhere. Anyone who opens that link sees your tracker and can choose to save it as their own; opening it on your laptop restores the same data you had on your phone.
How is the "safe to skip" number calculated?
Once you enter the Total Classes in Semester for a subject, the Tracker works out the most classes you can still miss and still land at or above your target by the end of the term — accounting for the classes already held, not just the ones left.
Why does the recovery number look different from a simple "classes needed" guess?
Attending a class adds one to both the classes attended and the classes held, so the percentage moves slower than a naive calculation suggests. The Tracker's recovery formula accounts for that growing denominator, so the number it gives you is the exact number of classes in a row that brings you to your target — not an underestimate.