There is no official ILR-to-CEFR conversion table

Every hours-to-CEFR figure on the internet passes through a conversion that no standards body ever published. Published academic tables disagree by a full level. Here is which reading we take and why it makes our numbers larger.

Updated Sep 1, 2026Kevin Fan

The current NFATC page publishes timelines to an integrated ILR 3 in speaking and listening. Almost every learner thinks in CEFR — A1 through C2. So every attempt to restate those timelines as "hours to B2" or "hours to C1", including on this site, has passed through a conversion between the two scales.

No standards body has ever published that conversion.

Two scales that were never designed to meet

The Interagency Language Roundtable scale is a US federal instrument, 0 to 5, built to describe what a government employee can do in a posting. The Common European Framework of Reference is a Council of Europe instrument, A1 to C2, built to describe what a learner can do and to make qualifications comparable across European countries.

Different origins, different purposes, different decades. Neither body has issued a crosswalk to the other, and neither has endorsed anyone else's.

What exists instead is a set of academic and institutional attempts, and they do not agree:

Some published tables place ILR 3 / 3+ at C1
Others place C1 nearer ILR 4

That is a full CEFR level of disagreement, at exactly the point where FSI's headline figure sits.

Why a level of ambiguity is a lot

Our own model, Spanish, one hour a day with a tutor:

Target	Hours
B2	529
C1	725

Choosing the wrong end of the disagreement moves an estimate by more than a third — before any question about your method, your background, or your consistency.

Every site quoting FSI hours in CEFR terms has made this choice. Most have made it without noticing there was one.

Which reading we take, and the direction of the error

Our model treats Spanish's current 30-week NFATC schedule — transparently derived to 690 class hours at 23 per typical week — as roughly C1.

That is a modelling choice, not an official crosswalk. It makes our estimates larger than mappings that place the same NFATC endpoint below C1, because C1 receives the full baseline rather than a fraction of it. The uncertainty is greater than older S-3/R-3 comparisons imply: the current endpoint integrates speaking and listening, while many published crosswalk attempts compare different skill profiles.

Two reasons for taking the conservative side:

An overestimate fails safely. Someone who budgets 725 tutor hours and needs fewer has a pleasant surprise. Someone who budgets too little may abandon the language and conclude they are bad at languages.

The commercial incentive runs the other way. A site funded by course referrals benefits from small, encouraging numbers — they make products look more capable. Taking the reading that inflates our own figures is the cheapest possible way to demonstrate the matching rules are not tuned for conversion. How this site is paid for sets out the rest.

The general lesson

The chain behind "X hours to B2" for any language, on any site, is:

NFATC's published or transparently derived class-hour baseline to integrated ILR 3 in speaking and listening — solid within its stated programme conditions
That integrated ILR endpoint → CEFR level — no official source, and crosswalk attempts use imperfectly matched skill profiles
CEFR level → your target level — derived from exam-preparation hour bands
Adjusted for method and background — estimated coefficients

Step 1 is the only one with an unambiguous published source. Steps 2 through 4 are interpretation, and a page that presents the output as a fact has quietly dropped three layers of it.

We mark all of them. Every estimate here carries its caveats, and the methodology page names each factor, its source, and its confidence — including the ones labelled as estimates, which is most of them below step 1.

Selected from the source graph, with fallback links that keep every article connected.

"Fluent" is not a level, and that is why the estimates disagree
NFATC publishes training timelines to an integrated ILR 3 in speaking and listening. CEFR describes what you can do. HSK claimed a mapping the CEFR bodies rejected. None of them define fluency, which is why two honest sources can differ so widely.
Where this model is wrong
Five errors this calculator has actually shipped, what each one produced, and what changed. Published because a site that traces other people’s sourcing failures should be able to show its own.
The current NFATC schedule implies 690 Spanish class hours, not 600
The State Department now lists Spanish at 30 weeks, with a typical week of 23 class hours and 17 hours of self-study. That makes 690 class hours to integrated ILR 3 in speaking and listening — not 600 hours of any study method.

Sources

Every figure above, and where it came from. A post that traces other people's unsourced numbers does not get to have any of its own.

Foreign Language Training — US Department of State, National Foreign Affairs Training Center
The current NFATC training timelines: a typical week is 23 class hours plus 17 hours of self-study, aimed at an integrated ILR 3 in Speaking and Listening. Category I lists 24–30 weeks; using the page's typical class week, this site derives 552–690 class hours. Categories II–IV print 828, 1,012 and 2,200.
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.
Guided learning hours — Cambridge English
The cumulative shape between CEFR levels. Cambridge publishes guided-learning-hour bands for its English qualifications (A2 180–200, B1 350–400, B2 500–600, C1 700–800, C2 1,000–1,200). Our factors are normalised against C1 rather than fitted to every band; for example, 0.27 × the 750-hour C1 midpoint is 202.5, just above the A2 band.