SRS workload simulator

This page answers “how heavy will my reviews get?” with a calculator you can read even if JavaScript is off. Change new cards, study days, retention, vacation, and seconds per review. The default table uses 10 new items a day, 90% retention, seven study days, two vacation weeks, and eight seconds per review.

The model is simplified on purpose. Real Anki FSRS and WaniKani scheduling differ. Use this page to see the shape of the queue, then confirm the actual product on its official docs.

The published model

Each new item is introduced on a study day and reviewed at these offsets, in days after introduction:

Review	Day after introduction
1	1
2	3
3	8
4	21
5	55
6	145

That ladder is a 2.5x-ish progression used only here. It is not Anki’s graduating interval, not FSRS, and not WaniKani’s hour-based stages.

Retention scales the review count against a 90% baseline:

multiplier = (retention / (1 - retention)) / 9

At 90% the multiplier is 1. At 95% it is higher. That matches Anki’s official FSRS note that workload rises quickly above 90%. It is still not FSRS.

Rest days and vacation weeks do not delete reviews. They move due work to the next study day. Vacation weeks are modeled as consecutive non-study days starting at the midpoint of the 365-day horizon.

WaniKani-scale preset

The WaniKani preset uses official floors, not a scraped item census:

• Over 2,000 kanji and over 6,000 vocabulary words, from WaniKani’s content page (checked 1 Sep 2026). The calculator adds those floors to 8,000 items. Radicals are extra and are not in that sum.
• Level 60 is a published official curriculum page (checked 1 Sep 2026). This page uses it as the end-of-path marker. It does not invent a per-level item table.
• WaniKani’s homepage says “2,000 kanji. 6,000 vocabulary words. In just over a year.” Its knowledge base says members reach about 2,000 kanji in one or two years. Those are WaniKani’s statements. This simulator does not measure them.

Introduction time in the calculator is items / new cards per study day, stretched by rest days. It is time to introduce the published floors, not time to Guru, Burn, or “finish Japanese.”

Official schedules this model is not

System	What the official page says	Used here as
This simulator	1, 3, 8, 21, 55, 145 days	The projection
WaniKani SRS stages	4h, 8h, 1 day, 2 days, 1 week, 2 weeks, 1 month, 4 months to Burned	Citation only
Anki FSRS	Default desired retention 90%; workload rises quickly above that	Retention slider baseline
Anki SM-2	Learning steps, then increasingly long review delays	Why a growing ladder exists

WaniKani also accelerates the first two levels. This page does not copy that exception.

How to read the numbers

• Peak day is the worst study day in the year-long window.
• Typical study day averages only days you actually study.
• Three skipped days piles the reviews that would have been due around week 13 onto the return. That is a snapshot, not a promise.
• If minutes exceed a normal weekday, cut new cards. The SRS burnout guide is the workflow version of the same advice.

Inku is not the default recommendation here. This tool is about queue math. Inku fits later only if you want prepared iPhone cards with low setup. For custom decks use Anki. For a fixed kanji path use WaniKani. Compare them on Anki vs WaniKani and the flashcards and SRS hub.