A complete guide to spaced repetition timetables, the science behind the intervals, and tools to automate the entire system
| Review Session | Interval | Day (from Day 0) | Approx. Retention Before Review |
|---|---|---|---|
| Initial learning | — | Day 0 | 100% (just learned) |
| 1st review | 1 day | Day 1 | ~33% (forgetting curve dip) |
| 2nd review | 2 days | Day 3 | ~60–70% (curve flattening) |
| 3rd review | 4 days | Day 7 | ~70–80% |
| 4th review | 7 days | Day 14 | ~80% |
| 5th review | 16 days | Day 30 | ~85% |
| 6th review | 30 days | Day 60 | ~90% |
| 7th+ reviews | Growing (60+ days) | Day 120+ | Near-permanent retention |
This is a simplified fixed schedule. Adaptive algorithms (Anki, SM-2, FSRS) adjust intervals dynamically based on your individual performance on each card.
Spaced repetition is a study technique that schedules review sessions at systematically increasing intervals. Instead of studying the same material every day (or cramming it all at once), you review it just before you're about to forget it — which creates the strongest possible memory reinforcement.
The principle is based on the spacing effect — one of the most consistently replicated findings in cognitive psychology. Reviewing something after a gap is harder than reviewing it immediately, and that difficulty is precisely what makes it more effective. The extra cognitive effort required to retrieve a fading memory strengthens the neural pathway far more than reviewing something you still remember perfectly.
Review on Days 1, 3, 7, 14, and 30 after first learning. This is the most commonly recommended fixed interval schedule and works well for most students.
Best for: Students who want a manual system they can follow without software. Works well for exam prep with a defined end date.
Cards are sorted into boxes 1–5. Cards in Box 1 are reviewed daily. Correct answers move a card to the next box (reviewed less frequently). Wrong answers send it back to Box 1.
| Box | Review frequency |
|---|---|
| Box 1 | Every day |
| Box 2 | Every 2 days |
| Box 3 | Every 4 days |
| Box 4 | Every 8 days |
| Box 5 | Every 16 days |
Best for: Physical flashcard users. Simple enough to run with paper cards and no software.
The SuperMemo SM-2 algorithm calculates individual intervals for each card based on your performance rating (1–4). Cards you find easy get pushed further out; difficult cards come back sooner. Intervals grow exponentially with an "easiness factor" that adjusts to your performance.
Best for: Long-term, large-scale learning (e.g., medical school, language acquisition). Requires software. This is what Anki uses.
The newest algorithm (2022), built into modern versions of Anki. Uses a more sophisticated memory model that accounts for stability and difficulty separately. Research shows it reduces review time by ~20% compared to SM-2 while maintaining the same retention rate.
Best for: Power users who want maximum efficiency and are comfortable enabling it in Anki settings.
If you have a fixed exam date, here's how to structure your spaced repetition schedule:
Work backwards from your exam date
For the best results, you want to complete your 4th–5th review 1–2 days before the exam. That means you need to start learning material at least 30–45 days before the exam for it to be well-consolidated.
Divide content into weekly learning batches
Don't try to learn everything at once. Introduce 20–50 new cards per day (depending on volume), and let the algorithm schedule reviews alongside the new learning.
Set a daily review cap
Commit to clearing your daily review queue every day without fail. Missing days causes cards to pile up exponentially. A 20-minute daily habit beats a 3-hour weekly session.
Stop adding new cards 2 weeks before the exam
New cards won't have time to go through enough review cycles to be consolidated. Focus the final 2 weeks on reviewing existing cards and doing practice questions.
Use our free calculator to generate your timetable
Enter your exam date and the topics you need to cover — the calculator outputs an optimised day-by-day review schedule.
Stop calculating intervals manually. Our free tools generate your complete review schedule automatically — and StudyCards AI creates the flashcards from your notes so you can focus on studying, not scheduling.
Or create AI flashcards from your notes — the fastest way to build your spaced repetition deck
For beginners, the 1–3–7–14–30 schedule (reviewing on days 1, 3, 7, 14, and 30 after learning) is the most practical. It's easy to follow manually and closely approximates what adaptive algorithms would recommend for average-difficulty material. As you get more experience, using Anki with FSRS will give you better personalisation.
Most Anki users find 10–30 new cards per day sustainable long-term. Medical students often push to 50–100 during intensive periods. Each new card creates future review obligations, so adding too many at once leads to overwhelming review queues. Start low and increase as you calibrate your pace.
Missing a day causes overdue cards to accumulate. When you return, don't try to do everything at once — set a daily limit and work through the backlog over several days. Adaptive algorithms will adjust intervals forward from whenever you actually review, so the schedule self-corrects. Consistency is more important than perfection.
Anki is the gold standard for spaced repetition and is free (on desktop and Android). Its algorithm (especially FSRS) is extremely well-optimised. The main limitation is that creating cards manually is time-consuming. Many students use StudyCards AI to generate Anki-ready cards from their notes, then import and study in Anki — getting the best of both tools.
You'll notice dramatically better retention within 2–3 weeks of consistent use. The compounding effects become very apparent after 1–2 months, where cards you learned weeks ago feel effortlessly familiar while requiring only a few minutes of review per week to maintain.
References
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