Exam Timetable Generator
Exam timetabling has one hard rule and everything else is preference: no student may be in two places at once. That rule turns a timetable into a colouring problem, where two exams sharing even a single student cannot share a slot. This generates a cohort, works out which exams genuinely conflict, and fits them into as few slots as the greedy rule manages — then checks the result by walking every student's whole enrolment rather than trusting the construction.
What this generator does
Builds a cohort of students with course enrolments, derives which exams share a student, then assigns slots most-constrained-first so no conflicting pair collides. The finished timetable is checked student by student, not pair by pair.
How to use this tool
- Choose how many exams, how many students, and how many courses each takes.
- Generate, and read how many slots were needed.
- Look at which exams shared a slot — those are the ones with no student in common.
- Raise the courses per student to watch the slot count climb.
Understanding the controls
- How many exams
- Between 3 and 14 subjects. More exams need more slots only when they actually share students.
- How many students
- More students means more distinct course combinations, so more pairs of exams end up in conflict.
- Courses each student takes
- This drives the difficulty far more than the other two: every student taking one more course adds a burst of new conflicts.
Common use cases
- Practising timetable construction with a cohort that actually clashes
- Showing why exam scheduling is graph colouring in disguise
- Producing a sample timetable for a planning exercise
- Teaching the difference between a hard constraint and a preference
- Generating test data for a scheduling tool
How this generator works
Two exams conflict when at least one student takes both, which makes the exams a graph and a slot a colour. Exams are then scheduled most-constrained-first — the one clashing with most others gets the earliest free slot — because leaving the hardest exam until last is how a timetable ends up needing an extra slot it did not need. That rule is quick and not always the fewest, so every timetable with one slot fewer is then tried, and tried again, until none works; where the search finds a shorter timetable than the rule did, that is the one shown and the notes say so. The result is verified by walking every student's own list of exams and confirming their slots are all different, which catches an error the pairwise construction could hide.
Randomness and fairness
Uses your browser's cryptographic random source to build the cohort by default. A seed reproduces the same students and the same timetable, which is deterministic and not cryptographically secure.
For how randomness is produced across the whole site, see how Generate Random works.
Limitations and good to know
- The fewest slots is proved by trying every timetable, which is affordable only because the page stops at fourteen exams; a real cohort of sixty papers needs a method that settles for a good timetable it cannot prove is the shortest.
- Only the clash rule is enforced — room capacity, invigilators, back-to-back exams and reading time are all real constraints this ignores.
- Students are generated rather than imported, so this is for practice and demonstration, not for timetabling an actual cohort.
- Every slot is treated as identical, so an exam that must be in the morning cannot be pinned.
Privacy and your data
The cohort and the timetable are generated in your browser. Neither is transmitted, and no real student data is involved at any point; what is measured is that the tool was used.
Related generators
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- Classroom Seating Chart GeneratorRandomise a classroom seating chart while keeping your own rules — front seats, pairs kept apart, pairs kept together and pinned seats.
- Revision Schedule PlannerSpreads topics across widening review gaps before an exam, fitting the gaps to the days you have and starting each topic on its own day where there is room.
- Mark Scaling CalculatorScales a set of raw marks to a target mean and spread, and is explicit about what clipping at the ends costs.
- Study Method PickerA well-known study technique to try, distinct from a single quick study tip.
- Rehearsal Schedule GeneratorTurns a list of scenes and who is in them into a call sheet where nobody is wanted in two places at once.