The problem: cramming feels productive and fails anyway
The week before an exam, you study for six hours straight. You feel prepared. The next morning, half of it is gone. This is not a failure of effort. It is a failure of scheduling.
The reason is the forgetting curve. Hermann Ebbinghaus ran experiments on himself in 1885, memorizing lists of nonsense syllables and testing his recall at intervals. The decay is predictable: memory drops fast in the first hour, then slower. Within a day, roughly 70 percent of what you learned is gone — unless you reviewed it, in which case the curve flattens and the next drop-off is pushed further out.
The fix is not more hours. The fix is the same hours, distributed across days, with reviews inserted at the moments the curve is about to drop. A study plan that spaces topics and schedules reviews outperforms the same total hours crammed into one block. This is the spacing effect, and it is the most replicated finding in the psychology of learning. It has held up across languages, age groups, and material types for 140 years.
The Study Plan Generator builds a calendar from your exam date, daily hours, and subject list. It distributes topics across the available days and inserts a review every third day. It exports to CSV and to an iCalendar file you can import into Google Calendar or Outlook.
Fastest path
Open the Study Plan Generator. Set the exam date, set the daily study hours, and list your subjects with a difficulty (1-5) and topic count for each. Click Generate. The tool produces a calendar grid with each day's topics and reviews, color-coded by subject. Export the plan as CSV (for a spreadsheet) or ICS (to import into a calendar app). The tool only shows the first 42 days in the browser; for longer plans, use the export.
The forgetting curve, and what a review actually does
Ebbinghaus modeled recall as roughly exponential: the probability of remembering after time t is J ≈ e^(-t/S), where S is the strength of the memory. A fresh memory has low S; an old, well-reviewed memory has high S. The higher the strength, the slower the decay.
A review does two things. First, it restores what has decayed — you retrieve the material, which re-encodes it. Second, and more important, it increases S, so the next decay is slower. The first time you learn something, you might forget 70 percent in a day. After one review, you forget 70 percent in three days. After two reviews, in a week. After three, in two weeks. Each review roughly multiplies the time until the next drop-off.
This is why spacing works. A review given at the moment the memory is about to decay does more for retention than the same review given immediately after learning (when the memory is still strong) or months later (when it is gone). The interval should expand as the memory strengthens. A fixed interval is a rough approximation; an expanding interval is the real thing.
Active recall: the retrieval is what builds the memory
Re-reading notes feels like studying. It is not. The single act that builds memory is retrieval — pulling the information back out of your head, not pushing it back in.
The evidence is strong. A 2013 study at Purdue had students study science texts. One group re-read the material. The other group retrieved it, by trying to recall what they had read without looking. A week later, the retrieval group remembered about 50 percent more. The retrieval practice had consolidated the material; the re-reading had not, even though both groups spent the same time and both groups felt equally prepared (a common finding — students' sense of how well they have learned is a poor predictor of how well they will actually perform).
What this means for a study plan: the sessions that matter most are not the ones where you read the material for the first time, but the ones where you force yourself to remember it. Review days are not a warm-up. They are the load-bearing wall. Flashcards (the Vocabulary Builder is a flashcard tool with a quiz mode) work precisely because they force retrieval on every card.
Interleaving: why mixing beats blocking
The intuitive way to study is blocking: master topic A, then topic B, then topic C. The evidence says interleaving — mixing A, B, and C within the same session — transfers better, even though it feels harder and slower in the moment.
A classic 2007 study by Rohrer and Taylor had students learn to compute the volume of four solid shapes. One group practiced each shape in a blocked order (eight problems of one shape, then eight of the next). The other group interleaved (the same problems, mixed). On the test the same day, the blocked group scored higher — interleaving feels harder, and the short-term performance looked worse. A week later, the interleaved group outperformed the blocked group by a wide margin. The mixed practice had forced the students to discriminate between the shapes, which is what they needed to do on a real test.
The Study Plan Generator assigns subjects in blocks: all of subject A's topics first, then subject B's. That is blocking, not interleaving. If you want the interleaving benefit, you will need to reorder the plan — or work on more than one subject in a single day's block. The tool gives you the raw schedule; the sequencing within a session is your call.
How the tool distributes topics
The tool's algorithm is straightforward. It takes your total topic count across all subjects, divides it by the number of days to the exam, and assigns floor(daily hours) new topics per day. Once the new topics are exhausted, the remaining days fill with generic "Review & Practice."
Every third day, it inserts a review by pulling the first task from three days earlier. This is a fixed-interval review scheme — the interval is always three days, never expanding. It also only reviews the first task of the source day, so most topics never get a scheduled review. The tool labels this "spaced repetition," but it is a rough approximation: a real spaced-repetition system schedules every item at its own expanding interval, not one item at a fixed interval.
There is one thing worth knowing about the difficulty field. The tool asks for a difficulty (1-5) per subject, and you might assume harder subjects get more time. They do not. The difficulty is computed into a weight that is then discarded — the distribution is purely sequential. A subject with difficulty 5 and one with difficulty 1 each get one slot per topic. If you want a harder subject to get more time, you have to give it more topics in the input, not a higher difficulty.
Spaced repetition done right
The tool's three-day fixed cycle is a nod to spaced repetition. Real spaced-repetition systems — SM-2 (the algorithm Anki uses), FSRS, the Leitner system — schedule each item at its own interval, and the interval expands with each successful review.
SM-2 works like this. Each item has an ease factor (starting at 2.5) and an interval. After each review, you grade your recall (0 to 5). If you passed, the next interval is the previous interval times the ease factor; the ease factor drifts up or down based on how hard the item was. A new item might be reviewed at 1 day, then 3 days, then 7 days, then 16 days, then 35 days. The interval expands because the memory is getting stronger, so the next review can wait longer.
The reason the expansion matters is that it concentrates reviews where they are needed. A fixed three-day cycle reviews easy items too often (wasting time) and hard items too rarely (letting them decay). An expanding interval reviews each item just before it would have been forgotten, which is the moment a review does the most good.
For most students, a full SM-2 implementation is overkill for exam prep — it pays off over months and years, not over a few weeks. But the principle is worth knowing: if you are going to review, review at the moment you are about to forget, not on a fixed schedule. The tool's three-day cycle is a usable approximation for short exam timelines where the expansion would not have room to grow.
Time-boxing and rest
The tool asks for daily study hours and converts them to a number of topics per day. It does not break the day into work sessions. For that, the Pomodoro Technique is the standard: 25 minutes of focused work, 5 minutes of break, repeat. Four work sessions, then a longer break. The Pomodoro Timer handles the timing.
Pomodoro works for two reasons. First, it time-boxes the work, which makes a long study session feel like a sequence of short, finishable tasks instead of an open-ended slog. Second, the breaks matter. Attention drifts after about 20-30 minutes of continuous focus; a short break resets it. Long sessions without breaks produce diminishing returns — the fourth hour of unbroken study is far less productive than the first.
Rest days matter even more. Memory consolidation happens during sleep, specifically during slow-wave and REM sleep. The neural traces laid down during the day are replayed and stabilized overnight. Skipping sleep to study more trades the encoding time for the consolidation time, and the net is usually a loss. The tool does not schedule rest days — every scheduled day gets the same load. If you are studying for more than a few weeks, build in a day off each week, even if the tool's calendar does not show one.
Gotchas
- The difficulty field does not affect scheduling. The tool asks for a 1-5 difficulty per subject but computes a weight from it that is never used. Distribution is purely sequential. If you want a harder subject to get more time, increase its topic count, not its difficulty.
- "Spaced repetition" here is a fixed three-day cycle, not an expanding interval. Real spaced-repetition systems (SM-2, Anki, FSRS) schedule each item at its own expanding interval — 1 day, 3, 7, 16, 35 — based on how well you recalled it. The tool reviews one item every three days, at a fixed interval. For short exam timelines this is a workable approximation; for long-term retention it is not.
- Subjects are blocked, not interleaved. The tool assigns all of subject A's topics, then all of subject B's. Interleaving (mixing subjects within a session) transfers better, per the evidence. If you want the interleaving benefit, reorder the plan or work on two subjects per day.
- Reviews only re-surface the first task of each three-day-old day. Most topics never get a scheduled review in the tool's output. If you want every topic reviewed, you will need to track that yourself, or use a dedicated spaced-repetition tool for the review layer.
- The plan does not persist. Refresh the page and the plan is gone. Export to CSV or ICS before you close the tab, or you will have to regenerate it from the same inputs.
- The browser shows only the first 42 days. For longer plans, the UI truncates. Use the CSV or ICS export to see the full schedule — the export includes every day.
Summary
- The forgetting curve describes how memory decays after learning — fast at first, then slower, roughly exponentially. A review at the moment the curve is about to drop flattens it and strengthens the memory, so the next decay is slower. This is the spacing effect: the same total hours, distributed across days with reviews, outperform hours crammed into one block.
- Active recall (retrieval practice) is what builds memory, not passive re-reading. A study session that forces you to produce the material — flashcards, practice problems, self-testing — does more than one where you re-read notes. Review days are the load-bearing part of a study plan, not a warm-up.
- Interleaving (mixing topics within a session) transfers better than blocking (mastering one topic before moving on), even though it feels harder. The Study Plan Generator blocks subjects sequentially; if you want the interleaving benefit, reorder the plan or work on multiple subjects per day.
- The tool's spaced repetition is a fixed three-day cycle, not an expanding interval. Real spaced-repetition systems (SM-2, Anki) schedule each item at its own expanding interval based on recall quality. The tool's approximation works for short exam timelines but not for long-term retention. The tool's difficulty field is collected but not used in scheduling.
- Time-boxing with breaks (the Pomodoro Technique) makes long sessions productive by resetting attention. Rest days and sleep matter because consolidation happens overnight — the day you learn is not the day the memory sets. The tool does not schedule rest days; build them in yourself for plans longer than a few weeks.
- Use the Study Plan Generator for the calendar, the Vocabulary Builder for retrieval-practice flashcards, the Pomodoro Timer for time-boxed sessions, and the Citation Generator for the papers the exam is based on.