The Leitner system: the 5-box flashcard method
The Leitner system is a way to study flashcards so that you spend most of your time on the cards you don’t know yet. Cards live in numbered boxes; get one right and it moves up to a box you review less often, miss it and it goes back to box 1.
- A
- B
- C
- D
- E
- F
- G
- H
All 8 cards start in box 1.
How the Leitner system works
German science journalist Sebastian Leitner described the method in his 1972 book So lernt man lernen (“How to learn to learn”). It is spaced repetition you can run with a shoebox:
- All new cards go in box 1.
- Review box 1 every session, box 2 every second session, box 3 every fourth, and so on. The exact rhythm matters less than the principle that higher boxes are reviewed less often.
- Right answer: the card moves up one box.
- Wrong answer: the card goes all the way back to box 1, whatever box it was in.
- A card that survives box 5 is learned. Retire it, or check it once before the exam.
In the simulator above, watch card F when “hard” is ticked: it keeps dropping back, so it gets reviewed every session while the easy cards drift up and out of the way. That is the whole trick. You never waste time re-flipping cards you already know.
A common Leitner schedule
| Box | Review | If you study daily |
|---|---|---|
| 1 | Every session | Every day |
| 2 | Every 2nd session | Every 2 days |
| 3 | Every 4th session | About twice a week |
| 4 | Every 8th session | About weekly |
| 5 | Every 16th session | About every two weeks |
Some versions use three boxes, others seven. Fewer boxes suit a test that is close; more boxes suit something you want to remember for months.
Doing it on paper
You need five envelopes or a box with four dividers, and cards you’ve written or printed from the flashcard maker. Mark the box numbers, keep a note of which session you’re on, and follow the schedule. The rule that matters most is being honest: if you hesitated or only half-knew it, it goes back to box 1.
Doing it online
StudyBlitz’s study mode runs the same rules: every “Got it” moves a card up a box and every “Missed it” sends it to box 1. With “Weakest boxes first” on, each session starts with box 1. Boxes are saved per deck in your browser.
Questions people ask
Who invented the Leitner system?
Sebastian Leitner, a German science journalist, in his 1972 book So lernt man lernen. It builds on earlier research on spaced review by Hermann Ebbinghaus and others.
What is the fastest way to memorize flashcards?
Answer each card from memory before flipping, keep cards to one fact, and review the ones you miss most often, which is exactly what the Leitner boxes do. Short daily sessions beat one long session.
What is the difference between the Leitner box and the Leitner method?
They mean the same thing. The box is the physical set of compartments; the method is the rule for moving cards between them: right answers move up a box, wrong answers go back to box 1.
How many boxes should I use?
Five is the classic number. Three works for a test in a week or two; more boxes spread reviews further apart for long-term learning.
What happens when I get a card wrong?
In the standard system it goes straight back to box 1, even if it was in box 5. Some people use a gentler version that drops it one box, which is slower to correct real gaps.
Is the Leitner system better than Anki?
Anki uses a finer-grained algorithm that schedules each card individually, which helps with very large decks. Leitner is simpler, works on paper and is plenty for class tests.