Free tool · Spaced repetitionHow many reviews will
your new words bring?

How the numbers are worked out

The calculator adds your new words each day and answers every card on the day it is due, through the same scheduling code the Lexpad app runs (its srs.ts, fsrs.ts and schedule.ts, copied unchanged from commit cab4d98). Before it went live, that copy was run against Lexpad’s 165 shared test cases for the schedule, the same ones the app and the server must pass.

• Boxes: a new word is asked the day you add it, then after 1, 3, 7 and 21 days. Box 5 counts as mastered; a mastered word you still know waits 45, 90, 180 and then 365 days. A miss sends a word back to box 1, asked again the same day.
• Misses in Boxes: after a word’s first answer, each answer is missed at the rate you choose, at random but from a fixed sequence, so the same inputs always give the same numbers. A word missed is retried once that day and answered right.
• Smart (Beta): FSRS-6 with its published default parameters. Each answer is right with the chance FSRS itself predicts for that day, and each gap is set so that recall falls to your target. Mastered means the same in both: a word in box 5 (in Smart, a memory that lasts 21 days or more).
• Cards a day are 7-day averages; minutes use the app’s own estimate on Today, about 0.4 minutes a card.

Left out of this version: a daily review limit (Most reviews a day) and the pause of new words it brings, Personal tuning of Smart, “Go back two boxes” after a miss, days you skip, and games and extra practice, which never move a schedule.

Boxes or Smart?

Boxes give every word the same fixed steps, so the numbers are easy to predict. Smart works out a gap for each word from your own answers, aiming at the share you want to remember. A higher target means shorter gaps and more reviews a day; the Anki manual says the same about its own FSRS target (Anki manual, deck options). Neither is promised to be lighter: it depends on your answers. Compare them in more depth in Leitner boxes or FSRS?

Choosing your pace

• 5 a day if you have about ten minutes.
• 10 to 15 a day for a steady routine.
• 20 or more only for a short push with time every day.

Why, and what each pace costs over a year: How many new words a day should you learn?