Start Here: How to Set Up a Leitner System

What You Need

• Index cards — 3×5 or 4×6. Lined or blank both work.
• 3 to 5 boxes or compartments — Shoeboxes, pencil cases, recipe card boxes, or labelled envelopes.
• A pen — Write by hand. It improves encoding.
• 15–20 minutes per day — The system only works if you review consistently.

That’s it. The Leitner system has no required apps, no subscriptions, no syncing issues, and no battery.

Step 1 — Write Your First Cards

The most common mistake is writing bad cards. A bad card is one that tries to test too many things at once. The rule is simple:

One fact per card. Front: a specific question. Back: a short answer (1–5 words).

Bad card: Q: What is the mitochondria? A: The organelle responsible for producing ATP through cellular respiration, known as the powerhouse of the cell.

Good card: Q: What does the mitochondria produce? A: ATP

Write your first 5–10 cards now. Put them all in Box 1.

Step 2 — Label Your Boxes

Label three boxes (or envelopes, or compartments in a recipe card box) as Box 1, Box 2, and Box 3. If you want to start with five boxes, that’s fine too — see the 5-Box Schedule.

Basic intervals for a 3-box system:

• Box 1: Review every day.
• Box 2: Review every other day (Mon, Wed, Fri, Sun).
• Box 3: Review every 4 days.

Download the free printable box labels if you want something to tape on your boxes.

Step 3 — Your Daily Review Routine

Your review session should take 10–20 minutes. Here’s the process:

1. Check your schedule — which boxes are due today?
2. Start with Box 1 (always review Box 1 every day).
3. For each card: read the question, say the answer out loud, then flip.
4. Correct (no hesitation) → move the card forward one box.
5. Wrong, slow, or unsure → back to Box 1.
6. Work through each scheduled box in order.
7. Stop when you’re done or at 20 minutes — don’t try to clear every card if you’re short on time.

The hesitation rule: If you paused more than 3 seconds, it counts as wrong. This sounds harsh but it’s why the system works — you only pass cards you truly know.

Step 4 — Adding New Cards

Start with a maximum of 5–10 new cards per day. Not more. The biggest mistake beginners make is adding 50 cards in one sitting because they’re feeling motivated. Those 50 cards will pile up in Box 1, the daily review will take an hour, and the habit will collapse within a week.

10 cards a day = 70 cards a week = a sustainable, growing system.

When Box 1 has more than 30 cards, pause new additions until it drains.

What to Do When You Miss a Day

It happens. Don’t panic.

• If you missed one day: just resume your normal review. Box 1 will have accumulated. That’s fine.
• If you missed several days: spend 2–3 days clearing Box 1 before resuming normal reviews.
• If Box 1 is massive: follow the Backlog Rescue Plan.