FSRS has very few settings that matter to you. Most of the work is done by the scheduler. What is left is a short list of choices about how much you want to study, and in Cirello that list is three things: how high to aim your recall, how many new cards to take in each day, and how big a daily review you are willing to do. This guide explains each setting in plain terms, with sensible starting points and the signs that it is time to change them.
Key takeaways
- Desired retention is how likely you want to be to remember a card when it comes back. Start at 90%, the default, and change it only for a reason.
- Max new cards per day controls how fast your queue grows. A small number is easier to sustain than a large one.
- Daily goal caps how much scheduled review Cirello asks of you each day, by cards or by minutes.
- You do not need to tune FSRS parameters or press an "optimize" button. Cirello refits them from your own history once you have enough reviews.
- Change one setting at a time, then watch your queue for a couple of weeks before changing another.
What are the FSRS settings in Cirello?
Cirello keeps the study settings in one place: Account - Study & scheduling. The ones that matter are:
| Setting | What it does | Range or default in Cirello |
|---|---|---|
| Desired retention | The chance of recall the scheduler aims for at review time | 70% to 98%, default 90% |
| Max new cards per day | How many brand-new cards can be introduced each day | 0 to 200, default 5 |
| Daily goal | Stops scheduled review at a number of cards or minutes, or has no limit | Cards: 5 to 200, default 20. Minutes: 5 to 120 |
Each deck can also have its own review intensity, so a deck of facts you cannot afford to lose can be reviewed more often than a deck of long-term ideas.
How should you set desired retention?
Desired retention is a trade between memory and time. A higher target brings each card back sooner, so you remember more and review more. A lower target waits longer, so you review less and forget more. The full reasoning is in desired retention in FSRS, including why each extra point near the top costs more reviews than the last.
A practical way to choose:
- Leave it at 90% to begin with. It is the default for a reason: it is a reasonable balance for most material.
- Raise it for material with a cost for forgetting, such as a fixed exam date. Do it for a defined period and plan to relax it afterwards. An exam plan is the better tool for that, since it pulls reviews in before a date you set.
- Lower it if your daily queue feels heavy and you would rather forget a little more than quit. A habit you keep beats a target you abandon.
Because retention changes the gap for every card at once, a small change can be felt on a large library. Move it a few points, not twenty.
How many new cards per day should you add?
New cards are the part of the workload you control most directly. Fresh cards have short gaps, so they come back often in their first weeks, and each batch you add creates a bump of reviews that arrives soon after. The longer explanation, with a simple way to estimate your future queue, is in how many flashcards per day.
Cirello starts at 5 new cards a day, which is deliberately small. A reasonable path:
- Start small and review everything that is due before adding more.
- Watch the size of your daily queue for two weeks.
- Raise the cap only when the queue is comfortable, and lower it, or set it to 0, when it is not. Setting new cards to 0 is a perfectly good response to a heavy week; the queue shrinks as gaps stretch.
What does the daily goal do?
The daily goal is separate from new cards. It decides how much scheduled review Cirello asks for on a given day: stop after a number of cards, stop after about a number of minutes, or have no goal and review everything due. New cards always have their own cap, whichever goal you pick.
If you think in time ("I have fifteen minutes"), choose minutes. If you think in cards, choose cards. If you would rather see everything that is due, choose no goal, and keep an eye on the queue.
Do you need to optimize FSRS parameters?
In some spaced-repetition tools you press a button to optimize the parameters, and the usual advice is to do it now and then. In Cirello you do not. FSRS-6 has 21 parameters that describe how your memory behaves. They start at defaults, which are an average over many learners, and a background job refits them to your own review history when you qualify: at least 1,000 scheduled reviews, at least 7 days since the last fit, and at least one new review since then. Until then, the defaults apply and work fine. The mechanics are in inside Cirello's FSRS-6 pipeline, and the overall picture is on the FSRS app page.
When should you change a setting?
| What you notice | Setting to look at |
|---|---|
| The daily queue keeps growing and feels heavy | Lower max new cards per day first, then consider a lower desired retention |
| You finish quickly and feel you are forgetting too much | Raise desired retention a few points |
| An exam is coming | Use an exam plan rather than changing your everyday settings |
| You are going away for a while | Pause the account or a deck instead of changing retention |
| You cannot tell what is wrong | Check whether your cards are too big or too vague; see how to write good flashcards |
A starting setup
If you want a single answer to start with: keep desired retention at 90%, keep max new cards at the default, pick a cards-per-day goal that fits your time, and review every day for two weeks before touching anything. Then change one thing at a time. The best configuration is the one that you will still be using next month.
Written by the Cirello team; see about Cirello and how we write for our editorial approach. Questions or corrections? Contact us at [email protected] or through the support page.