FluencyClock

Tools

Which language could I actually reach?

Start from what you have rather than from what you want. This lists the languages that reach your target inside your window — and the ones that do not, because that is the more useful half.

Most people mean B2 when they say fluent.

The single biggest factor after the language itself — the spread between methods is wider than the spread between difficulty bands.

Beyond English. A related language can cut the total by a third.

A note before you run it: the hours are the largest factor in this decision and they are not the only one. Dutch is in the cheapest band and almost impossible to practise; Spanish beats Italian at identical hours because of what surrounds it. Nothing published measures that, including this.

How this is worked out

This runs the model backwards across every language at once. Your window and pace fix a budget of hours; each of the thirty-odd languages is then tested against your target level, with your background applied, and sorted into those that fit and those that do not.

Both lists are shown. The languages that do not fit are the more useful half — knowing that Mandarin costs roughly four times Spanish is the single most valuable fact in this dataset, and filtering it out to keep the answer positive would remove it.

It will return an empty list

If nothing reaches your target in your window, that is the answer. The tool then distinguishes whether time or your method is the binding constraint, because lowering the target, changing the method and extending the window are three different fixes and only one of them applies.

Every tool here can decline to answer, and that is the most useful thing they do.

Common questions

It says nothing fits. What do I change first?
The target, then the method, then the window — in that order of effect. B1 is roughly half of B2 in hours, so lowering one level is the largest single lever. Method is next and is worth up to a factor of three. Extending the window is the weakest of the three and the one people reach for first.
Why is the cheapest language not always the right choice?
Because hours are the largest input to this decision and not the only one. Dutch sits in the cheapest band and is among the hardest languages here to actually practise, since almost everyone you would practise with speaks better English than your Dutch. Spanish beats Italian at identical hours because of what surrounds it. Nothing published measures that, including this tool.
Does it consider what I want to use the language for?
No, and that is the input you should supply yourself before running it. This works out what is reachable; it cannot know that your grandmother speaks Cantonese or that your employer is opening an office in Warsaw. A language you have a reason for beats a cheaper one you do not, by a margin no hour figure reflects.

Sources

Everything this tool rests on. The FSI baseline is published; the factors applied on top of it are ours and are marked as estimates.

  1. Foreign Language Training — US Department of State, Foreign Service Institute

    The class-hour bands every estimate on this site starts from, and the definition of the proficiency they lead to (ILR Speaking-3 / Reading-3).

  2. FSI Language Difficulty Ranking — fsi-language-courses.org

    Which languages sit in which band. The State Department publishes the categories as an image, so per-language assignment comes from independent reproductions that agree with each other and with the official hour bands.

  3. Guided learning hours — Cambridge English

    The shape of the curve between CEFR levels. Cambridge publishes cumulative hours per level (A2 180–200, B1 350–400, B2 500–600, C1 700–800, C2 1,000–1,200); our level factors are normalised against the C1 band and every one lands inside its published range.

  4. ILR scale — Wikipedia

    That no official ILR-to-CEFR crosswalk exists. Published academic tables place ILR 3/3+ at C1; others put C1 nearer ILR 4. We take the lower reading, which makes our estimates the more conservative of the two.

  5. Zhongwen Shuiping Kaoshi (HSK) — Wikipedia

    That Hanban's claimed one-to-one HSK-to-CEFR equivalence was rejected by CEFR bodies and is disputed by the German and French associations of Chinese-language teachers, who place old HSK 6 nearer B2–C1 than C2.

This tool is free and carries no ads or affiliate links. It is funded by commission on some course links elsewhere on the site — which pages, and how that is kept out of the recommendations.

If you got something out of this and are not going to buy a course, you can buy me a coffee instead. Entirely optional, and it changes nothing about what the calculator tells you.