Spaced Repetition Calculator

Pick a start date (and, optionally, an exam or deadline) to get a review schedule with expanding intervals. Copy it or download it as a calendar file. Free, instant, no signup.

What is spaced repetition?

Spaced repetition means reviewing material at increasing intervals instead of cramming it in one sitting. The underlying spacing effect is one of the most replicated findings in memory research: Cepeda and colleagues' 2008 studies showed that spreading reviews out over time produces far better long-term retention than massed study, and Dunlosky and colleagues' 2013 review of learning techniques rated distributed practice among the most effective strategies available to students. The idea is simple: you forget fastest right after learning, and each successful recall makes the memory more durable, so reviews can be spaced further and further apart.

You do not need flashcards to benefit. Re-reading your notes and highlights on a schedule, self-testing, or explaining an idea from memory all count as reviews. If you want the background, read our guide to spaced repetition for readers or the spaced repetition glossary entry.

How the schedule is computed

The calculator uses a fixed expanding-interval schedule: reviews fall 1, 3, 7, 14, 30, 60, and 120 days after your start date. If you set an exam or deadline date, any review that would land after it is dropped, and a final review is always added on the day before the deadline so the material is fresh when it counts. Short runways simply produce fewer, tighter reviews; long runways stretch out to the full 120-day interval.

To be clear about what this is: a simple heuristic informed by the distributed-practice research above, not an adaptive algorithm. Systems like SM-2 or FSRS grade every recall and reschedule each item individually; this tool trades that precision for something you can actually put on a calendar in ten seconds. For most people planning reading reviews or exam revision, a predictable expanding schedule captures most of the benefit of spacing with none of the overhead.

How to use the calculator

  1. 1

    Enter your dates

    Pick the date you start studying (it defaults to today) and, if you have one, the date of your exam or deadline.

  2. 2

    Get your review schedule

    The calculator lays out reviews at expanding intervals of 1, 3, 7, 14, 30, 60, and 120 days after your start date, drops anything past your deadline, and adds a final review the day before it.

  3. 3

    Export the schedule

    Copy the schedule as plain text, or download it as an .ics file and import it into Google Calendar, Apple Calendar, or Outlook so each review shows up as an all-day event.

Frequently Asked Questions

What review intervals does this calculator use?
The calculator schedules reviews at expanding intervals of 1, 3, 7, 14, 30, 60, and 120 days after your start date. If you set an exam or deadline date, reviews that would fall after it are dropped and a final review is always scheduled for the day before the deadline, so you finish with the material fresh.
Is this the SM-2 or FSRS algorithm?
No. SM-2 and FSRS are adaptive algorithms: they ask you to grade every recall and then adjust each item's next interval based on how well you remembered it. This calculator is deliberately simpler. It uses one fixed expanding-interval schedule informed by distributed-practice research, which makes it useful for planning study sessions on a calendar even though it does not adapt to individual items.
Can I use spaced repetition without flashcards?
Yes. Spaced repetition is about when you revisit material, not the format. On each scheduled date you can re-read your notes and highlights, try to recall the key points from memory before checking them, explain the ideas to someone else, or solve practice problems. Highlighting what matters as you read (for example with Glasp) gives you a compact set of material to review on each date.
Why do the intervals get longer over time?
Because forgetting slows down after each successful review. Right after learning something you forget it quickly, so the first review comes after just one day. Each time you successfully recall the material, the memory becomes more durable and decays more slowly, so the next review can wait longer without you forgetting. Expanding intervals like 1, 3, 7, 14, and 30 days track that curve, which is why they retain more per minute of study than rereading everything every day.