fluent-sm2-calculator

SM-2 spaced repetition scheduling computes the next review date for vocabulary items by mapping your review score to a 0-5 quality scale, then updating the easiness factor, interval days, and repetitions to pace long-term retention.

To calculate the next review date with the SM-2 algorithm, grade your vocabulary practice answer on a 0-5 scale; the scheduler updates the item's easiness factor, interval days, and mastery level to set the exact due date.

SM-2 spaced repetition updates per-item vocabulary database fields including easiness factor, interval days, repetitions, mastery level, total reviews, and the next due date, routing each item to the proper review queue.

The SM-2 calculator enforces strict algorithm rules and applies safe defaults in edge cases, resetting repetitions and routing vocabulary items to the correct review queues to prevent scheduling errors.

Spaced repetition scheduling integrates with the plugin update workflow via update-db.py when available, automatically writing the updated easiness factor, interval days, and due date fields back to the spaced-repetition database.