Spaced Repetition Schedule Calculator
Build an expanding spaced-repetition review schedule with dates from a start day, first interval and ease multiplier.
How it works
Interval₁ = first · Intervalₙ = Intervalₙ₋₁ × multiplier · Review date = start + cumulative interval days
Spaced repetition fights the forgetting curve by reviewing material just as you are about to forget it, then stretching the gap each time you succeed. Starting from a short first interval and multiplying by an ease factor produces the classic expanding pattern — 1, 2, 4, 8 days and so on — so early reviews are frequent and later ones are rare. The bigger the multiplier the faster the intervals grow, trading fewer total reviews for a higher risk of forgetting between them.
Worked example
Starting on day 0 with a 1-day first interval and a ×2 multiplier, the reviews fall on days 1, 3, 7, 15, 31 and 63 — six sessions that stretch a single item's memory across two months.
Frequently asked questions
What ease multiplier should I use?
Around 2 is a common default. Use a smaller multiplier (1.5–1.8) for hard or high-stakes material so reviews stay closer together, and a larger one (2.2–2.5) for easy material you rarely forget.
How does this relate to apps like Anki?
It is the same underlying idea: an expanding interval scaled by an ease factor. Real apps adjust the multiplier per card based on whether you got it right, but a fixed schedule like this is a good manual approximation.
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This calculator is for educational purposes. Double-check important results before acting on them.