The Leitner system organises flashcards into numbered boxes based on how well you know them. You review Box 1 every day, moving correct cards forward and wrong cards back to Box 1. Cards that reach the final box are considered learned. Sometimes called “Leitner’s system” or the “Leitner card system,” it was developed by German science journalist Sebastian Leitner in the 1970s.
What the Leitner System Actually Is
At its core, the Leitner system is a physical implementation of spaced repetition — the practice of reviewing information at increasing intervals over time. The “spacing effect” has been studied since the 19th century and is one of the most replicated findings in cognitive psychology.
The genius of Leitner’s approach is that it makes spaced repetition tangible. Instead of trusting an algorithm you can’t see, you physically move cards between boxes. You can see how full Box 1 is. You can feel when your system is getting out of control. That physical feedback loop is something no app quite replicates.
How to Set Up Your Boxes
You don’t need anything special. Three shoeboxes, pencil cases, recipe card boxes, or even labelled envelopes all work. Label them Box 1, Box 2, and Box 3 to start. Download the free printable box labels to make this faster.
For a 3-box system: Box 1 every day, Box 2 every other day, Box 3 every 4 days. That’s the full schedule. Download the 3-Box Schedule for a printable version.
The Daily Review Process
Each morning (or whenever you review), follow this process:
- Check which boxes are scheduled for today
- Start with Box 1 — always
- For each card: read the question, recall the answer, flip
- Correct with no hesitation: move to next box
- Wrong, slow, or guessed: back to Box 1
- Work through scheduled boxes in order
- Stop at 20 minutes if needed
The hesitation rule: If you paused more than 3 seconds, count it as wrong. This is the mechanism that makes the system accurate.
Choosing Between 3, 5, and 7 Boxes
Start with 3 boxes. A 3-box system gives you the full benefit of spaced repetition with minimal overhead. Move to 5 boxes once your system is running smoothly and Box 3 is filling up. See the full comparison at 3 vs 5 vs 7 boxes.
Common Mistakes to Avoid
- Too many cards too fast: Maximum 10 new cards per day when starting
- Skipping Box 1: Box 1 is reviewed every day — no exceptions
- Moving slow cards forward: If you hesitated, it’s wrong — back to Box 1
- Bad card design: One fact per card, short answer — use the quality checklist
FAQ
Is the Leitner system the same as Anki? No. Anki uses the SM-2 algorithm with variable intervals. The Leitner system uses fixed intervals you control manually. Both implement spaced repetition; Leitner is simpler and more transparent.
How long does setup take? Under 10 minutes. Get boxes, label them, write 5 cards, start reviewing tomorrow.
Ready to run your whole Leitner system from one sheet?
The Leitner OS Dashboard is a Google Sheet with everything pre-built: a Due Today list, box-by-box counts, a rewrite queue for problem cards, and settings you can adjust in seconds. No app, no subscription, no installation.
- ✓ Know which cards are due today — automatically
- ✓ Spot backlog before it hits you
- ✓ Track which cards need rewriting, not just more repetition
- ✓ No app. No syncing. Just a Google Sheet.
One-time purchase. Make a copy in 30 seconds.