How long it actually takes to finish a big flashcard deck

"How long will this deck take me" has two different honest answers, and most people only ever hear the first one. The first answer is how long until you've seen every card once. The second, more important answer is what your daily review load looks like once spaced repetition starts resurfacing everything you've already learned - and that second number is the one that actually determines whether a big deck is sustainable.

Two clocks, not one

At a fixed pace of new cards per day, finishing a 1,000-card deck's first pass is simple division: 1,000 cards at 20 new cards a day is 50 days. What that calculation misses is that by day 20 or so, you're not just seeing 20 new cards a day anymore - you're also reviewing cards from 1, 2, 5, 7, 10, and more days back, all landing on the same day as your intervals start to overlap. The flashcard deck time estimator models both clocks: the new-card clock (when first exposure finishes) and the review clock (your steady-state daily card count once the deck matures), so you're not blindsided by a review pile a month in.

This is exactly the situation covered in studying a 1,000-card deck without burning out - the number that burns people out usually isn't the deck size, it's an undersized new-cards-per-day setting that looked fine on day one and became unsustainable by day thirty. Daily new card and review limits in Encodr is the product side of the same problem: those limits exist specifically to cap the review pile before it compounds.

Why deck size alone is a bad way to estimate this

A 500-card deck and a 5,000-card deck at the same pace don't just take 10x longer for the second one - the steady-state review load also converges to a different number, because more total cards in circulation means more reviews landing on any given day once the deck is mature. How we built a 6,900-card MCAT deck is the largest real example in Encodr's library, and its actual pacing looks nothing like "6,900 divided by days until the exam" - it's paced against the exam date the same way this tool paces against whatever date you give it.

Reading the estimate correctly

If the tool tells you your steady-state review load is more minutes a day than you're realistically going to sit down for, that's useful information before you start, not after: it means either the new-cards-per-day pace needs to come down, the seconds-per-card estimate needs to reflect how fast you actually answer (not how fast you'd like to), or the deck itself needs to be split into a smaller first target instead of one long slog. None of those are failures - they're the same planning how to build a study schedule before an exam already recommends, just applied to card count instead of hours.

The same "spread a big total across the days you have" math shows up outside flashcards too - see how many pages a night your reading list actually is for the reading-assignment version.