Quick answer
A bunk calculator tells you how many classes you can safely skip while staying above your attendance target. If you have attended A of T classes with a target g, you can skip about floor(A ÷ g − T) upcoming classes. Try it live below.
You can skip 2 classes
and stay at or above your 75% target
How many classes can you skip?
Enter your classes attended, classes held so far, and your attendance target. The calculator instantly tells you how many you can bunk — or how many to attend to recover.
Bunk calculator
Live results as you type.
How the bunk calculator works
The math is based on keeping your attendance ratio at or above your target g (for example 0.75 for 75%).
Classes you can skip = floor( attended ÷ g − total )
Classes you must attend = ceil( (g × total − attended) ÷ (1 − g) )
The first formula assumes every future class you skip adds to the total but not to attended. The second finds how many classes you must attend in a row to climb back to target.
Skipping vs recovering
- Above target? You have a buffer. The calculator shows how many upcoming classes you can miss before you hit the line.
- Below target? There is no buffer — you need to attend a set number of classes consecutively to recover. Missing more digs the hole deeper.
Bunk with intent. Save your buffer for days you genuinely need — a clashing deadline, illness, or travel — rather than spending it early in the term.
Smart bunking tips
- Track per subject, not just overall. Many colleges enforce attendance subject-by-subject, so one weak subject can bar you even if your average looks fine.
- Recalculate after every week. Your buffer shrinks as more classes are held.
- Never count cancelled classes in the total — they were never held.
- Leave a safety margin. Aim a few points above the minimum so a surprise absence never pushes you under.
Key takeaways
- A bunk calculator converts your attendance into a concrete "classes you can skip" number.
- Above target you have a buffer; below target you must attend consecutively to recover.
- Track attendance per subject and recalculate weekly.
- Keep a small margin above the minimum for emergencies.
Your bunk calculator, always in your pocket
ClassTrack tracks every class and runs the bunk calculation per subject in real time, so you always know your buffer before you skip.
Get ClassTrack freeFrequently asked questions
What is a bunk calculator?
How many classes can I skip and stay at 75%?
How do I recover if I am below target?
Do cancelled classes affect the calculation?
