Add 5-10 new cards per day in a mature SRS — this pace produces 50-100 daily reviews taking 10-15 minutes, which is sustainable indefinitely

Why This Is a Rule

Spaced repetition systems have a hidden cost structure that surprises most users. Each new card creates a review debt: the card will return for review approximately 7-10 times in its first month, then increasingly spaced reviews for months afterward. Adding 20 new cards today means 150-200 additional review sessions spread over the next 6 months. At scale, this debt accumulates into an unsustainable daily review load that causes system abandonment.

The 5-10 new cards per day rate is calibrated to produce a steady-state review load of 50-100 cards per day — a 10-15 minute daily session that most people can sustain indefinitely as a habit. This assumes an average retention rate of 85-90% (meaning most cards are being recalled successfully and spaced further apart). Below 5 new cards per day, the system grows slowly and may not feel worth the habit investment. Above 10, the review load escalates beyond comfortable daily practice within weeks.

Michael Nielsen's long-running Anki practice confirms this calibration: a sustainable practice requires moderate inflow balanced against the growing review obligations. The goal is a system you'll maintain for years, not a sprint you'll abandon in weeks.

When This Fires

• When establishing or maintaining a spaced repetition practice
• When daily review sessions are taking 30+ minutes (too many new cards were added)
• When deciding how many cards to create from a new learning session
• Complements One atomic fact per spaced repetition card, answer under one sentence — multi-component cards produce vague retrieval the algorithm cannot schedule (atomic cards) with the rate-limiting that keeps the system sustainable

Common Failure Mode

The enthusiasm spike: starting a new topic, creating 50 cards in one excited session, then drowning in 200+ daily reviews two weeks later. The review backlog grows until the daily session takes 45 minutes, the habit becomes aversive, and the system is abandoned entirely. A steady 5-10 per day produces the same total cards over time without the unsustainable spike.

The Protocol

(1) Set a daily new-card limit in your SRS settings: 5-10 new cards per day. Most SRS apps (Anki, RemNote) have this setting. (2) When creating cards from a learning session, create as many as you want but let the SRS meter them out at the daily rate. Excess cards queue for future days. (3) Monitor your daily review count: 50-100 reviews → sustainable, maintain pace. 100-150 reviews → borderline, reduce new cards to 5/day. 150+ reviews → unsustainable, pause new cards entirely until the backlog clears. (4) Never skip review days — each skipped day adds the skipped reviews to the next day, compounding the load. A 10-minute daily session is easier to maintain than a 40-minute session every 4 days. (5) If daily reviews consistently exceed your target, use the SRS's "suspend" or "bury" features to thin low-value cards from the deck rather than pushing through an aversive session.