FSI Language Difficulty Categories: Hours for Every Language

The Foreign Service Institute (FSI) has been training U.S. diplomats in foreign languages since 1947. Its four-category difficulty ranking is the most-cited answer to "how long does it take to learn this language?", because it comes from people who actually run the courses: full-time students, trained instructors, and a proficiency test at the end.

Below is every language on the current list, with the weeks and class hours the State Department publishes, a calculator that turns those hours into a date, and what the numbers do and don't mean when you're planning your own study.

On this page

FSI hours calculator

Pick a language, a goal (FSI's professional figure, or a rough CEFR level from A1 to C1) and how much you study a day. If you've already put hours in, add them and they come off the total.

FSI categories at a glance

FSI groups languages by how long its English-speaking students usually take to reach professional working proficiency. These are the figures on the State Department's page as of September 2026. Hours are class hours; weeks are full-time weeks.

FSI says its Category III list "is not exhaustive". If your language isn't in the table, FSI doesn't publish a figure for it. The closest listed relative is a reasonable starting guess (Catalan next to Spanish, Afrikaans next to Dutch), but it is your guess, not FSI's.

The four categories in plain English

Category I (24–30 weeks, 552–690 class hours). FSI's description is "languages close to English": the Romance and Scandinavian languages, plus Dutch. French and Spanish sit at the top of the range, 30 weeks; the rest are 24.

Category II (about 36 weeks, 828 class hours). German, Haitian Creole, Indonesian, Malay and Swahili. A small group, and a step up from Category I: about six more weeks of full-time class than French or Spanish.

Category III (about 44 weeks, 1,012 class hours). FSI calls these "hard languages", with "significant linguistic and/or cultural differences from English". It's the biggest group by far: Russian, Polish, Greek, Hebrew, Hindi, Turkish, Thai, Vietnamese and some thirty more.

Category IV (88 weeks, 2,200 class hours). The "super-hard languages": Arabic, Cantonese, Mandarin, Japanese and Korean.

Why older lists say 600–750 hours and Category V

If you've seen Spanish at 600 hours, Category I at “600–750 hours” or a “Category V”, you've seen an older version of the list, not a mistake. The numbers have moved twice.

600–750 hours (four categories, until early 2025). From at least 2018 the State Department's page gave the same weeks with more hours: Category I 24–30 weeks (600–750 class hours), Category II about 36 weeks (900), Category III about 44 weeks (1,100) and Category IV 88 weeks (2,200). That works out to 25 class hours a week. In early 2025 the page switched to today's 23-hour week, which gives 552–690, 828 and 1,012 hours. Category IV still says 2,200, although 88 weeks at 23 hours would be 2,024. Spanish moved too: it was listed at 24 weeks (600 hours) until late 2023 and now sits at 30 weeks with French, which is why so many sources still say “Spanish, 600 hours”.

Languages that have dropped off. The older Category III also listed Icelandic, Sinhala, Somali, Tagalog, Tamil, Telugu and Tibetan (and, in 2018, Hausa). None of them is on the current page. That doesn't mean they got easier: the page says its Category III list “is not exhaustive”, so it simply doesn't give a figure for them now. If you're learning Tagalog or Tamil, the old 44 weeks and 1,100 class hours is the last figure the State Department published.

Category V (five categories). Lists with a Category V are older FSI figures renumbered by third-party sites. A widely shared version, on Effective Language Learning, has Category I at 23–24 weeks (575–600 hours), German in Category II (30 weeks, 750 hours), Indonesian, Malay and Swahili in Category III (36 weeks, 900 hours), the big middle group in Category IV (44 weeks, 1,100 hours) and Arabic, Cantonese, Mandarin, Japanese and Korean in Category V (88 weeks, 2,200 hours). The same figures, credited to FSI, were on the FBI's National Virtual Translation Center site in the mid-2000s. Today's Category IV is that old Category V: the same five languages and the same 88 weeks.

And the “CIA language difficulty scale”? There isn't a published one. The CIA, like other U.S. agencies, rates a person's proficiency on the ILR scale, not how hard a language is, and what turns up under that name is the FSI list above.

Languages by category

• Category I: the easiest languages for English speakers, with guides for Spanish, French, Italian and Portuguese
• Category II: German, Indonesian, Swahili and the rest, plus how long German takes
• Category III: the full “hard languages” list, grouped
• Category IV: the hardest languages for English speakers, with guides for Japanese, Arabic, Korean and Mandarin
• The level behind the hours: the ILR scale explained and FSI hours vs CEFR levels

What FSI hours actually measure

FSI hours are full-time, classroom-based, professional instruction with trained instructors. FSI describes a typical week as 23 hours of class and 17 hours of self-study, and the class hours in the table don't include the self-study. For Category IV, counting both gives closer to 88 × 40 = 3,520 hours of total effort.

The target is an integrated score of 3 (speaking and listening) on the Interagency Language Roundtable scale, roughly upper B2 to low C1. That's professional working proficiency, not "fluent" in the colloquial sense, and well beyond conversational.

A rough rule of thumb: if your goal is B1, conversational, plan for about half the FSI hours. That's not an FSI number; it's a planning heuristic. Our B1 hours guide has more on that level, and our how long it takes to learn a language page applies the same idea to every level from A1 to C1.

Why the category matters for tracking

If you're learning Japanese, expecting Spanish-speed progress will gut your motivation by month 3. The category tells you what's reasonable. B2 hour expectations shift dramatically by category.

Set your tracker's goal pace accordingly. Using the half-the-hours rule, B1 is roughly 275–345 hours for a Category I language and about 1,100 for Category IV. At 30 minutes a day, that's about a year and a half to two years for Spanish or Italian, and around six years for Japanese. At an hour a day, halve those. Both paths are normal; they're just different lengths.

For Spanish speakers learning English

A lot of people search for FSI's hours for English, and there aren't any. FSI trains English-speaking diplomats to learn other languages, so every figure on its list assumes you start from English. It doesn't publish the reverse, and the 690 hours it gives for Spanish is not an official estimate for Spanish speakers learning English.

You can still reason about it. FSI's categories are mostly a measure of distance between two languages, and distance runs both ways. Spanish and English share an alphabet, a large stock of Latin-derived vocabulary (información/information, posible/possible) and a lot of sentence structure. So it's sensible to expect English to be a Category I-type distance for a Spanish speaker, and to use Category I's 552–690 class hours as a loose reference, not a promise.

Two things push it one way or the other:

• Harder: English spelling is irregular, and English has far more vowel sounds than Spanish's five, so pronunciation and listening often take longer than grammar.
• Easier: most Spanish speakers have heard English for years, through music, films, games and the internet, before they ever study it. That exposure is real hours, even if nobody counted them.

If you want a number made for learners of English, Cambridge English, which writes English exams, publishes approximate guided learning hours per CEFR level: about 350–400 hours to B1 and 500–600 to B2, counted from beginner. Those are classroom-style hours, so the same caution applies: log your own hours and see how your pace compares.

We go further into this, with timelines, in how long it takes a Spanish speaker to learn English.

Your real category: your own situation

FSI categories assume an English-native learner with no prior exposure. Your real category shifts based on:

• Prior languages (a Spanish speaker learning Italian skips a category, basically)
• Living in the country (more hours of exposure every day, so the calendar time shrinks)
• Heritage exposure (childhood exposure compounds enormously, even passively)

The honest version of "how long will this take?" is the FSI estimate adjusted for your situation, then stretched or shortened by your study intensity. Your tracker turns this from a guess into a number.

Using categories for goal-setting

If you're picking between two languages, the category is a real input. You're not "lazy" for picking Italian over Japanese — you're picking a 24-week course over an 88-week one. Both are fine; just go in eyes-open.

For a deeper dive on a specific Category IV language, see how to track your Japanese progress or our full breakdown of how many hours it takes to learn Mandarin Chinese.

Limitations

FSI numbers describe motivated adults with an aptitude for languages, in small full-time classes. Self-study with mediocre materials takes longer. Self-study with great materials and active output practice can come close. The number is a benchmark, not a destiny.

Track your actual hours and compare. After 200 hours, you'll know whether you're trending faster or slower than the FSI estimate. That's far more useful than the estimate itself.

FAQ

What are the FSI language categories?

They are the four groups the U.S. Foreign Service Institute uses to estimate how long English speakers take to reach professional working proficiency (ILR 3 in speaking and listening). Category I (24–30 weeks, 552–690 class hours) covers languages close to English such as Spanish, French and Italian. Category II (about 36 weeks, 828 hours) includes German, Indonesian and Swahili. Category III (about 44 weeks, 1,012 hours) includes Russian, Polish, Hindi and Turkish. Category IV (88 weeks, 2,200 hours) is Arabic, Cantonese, Mandarin, Japanese and Korean.

What are the US FSI language tiers?

“Tiers” is an informal name for the same four FSI categories. Tier or Category I is the fastest for English speakers (552–690 class hours) and Category IV the slowest (2,200 class hours). The State Department labels Category III “hard languages” and Category IV “super-hard languages”.

How many hours does FSI say it takes to learn Spanish?

FSI lists Spanish in Category I at 30 weeks, or about 690 class hours, for a native English speaker to reach professional working proficiency. French is the same. Italian, Portuguese, Dutch, Danish, Norwegian, Romanian and Swedish are 24 weeks, about 552 class hours.

How many hours does FSI say it takes to learn German?

FSI puts German in Category II: about 36 weeks, or 828 class hours, alongside Haitian Creole, Indonesian, Malay and Swahili.

How many hours does FSI say it takes to learn Japanese, Korean or Chinese?

All three are Category IV: 88 weeks, or 2,200 class hours. Arabic and Cantonese are in the same group. FSI's typical week also includes about 17 hours of self-study on top of 23 hours of class, so the total effort is higher than the class hours alone.

Does FSI publish hours for Spanish speakers learning English?

No. FSI trains English-speaking diplomats, so all of its figures assume a native English speaker learning another language. Because Spanish and English are closely related, Category I's 552–690 class hours is a reasonable loose reference for a Spanish speaker learning English, but it is not an official figure.

Are FSI hours the same as self-study hours?

No. FSI hours are full-time classroom hours with trained instructors, for adults with an aptitude for languages, plus self-study that isn't counted in the figure. An hour of an app or a TV show won't convert one to one. Use the FSI number as a benchmark and track your own hours to see how your pace compares.

Why do some lists say Category I is 600–750 hours?

That's the State Department's previous figure. Until early 2025 its page gave Category I as 24–30 weeks or 600–750 class hours, Category II as 900, Category III as 1,100 and Category IV as 2,200, which works out to a 25-hour class week. It now uses a 23-hour week: 552–690, 828 and 1,012 hours, with Category IV still listed at 2,200.

Is there an FSI Category V?

Not on the State Department's current list, which has four categories. Older third-party charts numbered FSI's figures in five groups, with Arabic, Cantonese, Mandarin, Japanese and Korean in Category V at 88 weeks (2,200 hours). Those are today's Category IV languages.

Is Tagalog on the FSI list?

Not any more. Tagalog was in Category III (44 weeks, 1,100 class hours) on the State Department's older list, the one with 600–750 hours for Category I. The current page doesn't list it, and says its Category III list isn't exhaustive. Icelandic, Tamil, Telugu, Sinhala, Somali and Tibetan were also on the older list and aren't on the current one.

What is the CIA language difficulty scale?

There is no published CIA language difficulty scale. U.S. government agencies, the CIA included, rate proficiency on the ILR scale. Lists shared under the CIA's name are the FSI categories.

Related reading: How Many Hours to Learn Korean? TOPIK Levels in Hours · How Many Hours to Pass Each JLPT Level? · How Many Hours to Reach B1? · The Easiest Languages for English Speakers · The Hardest Languages for English Speakers · FSI Hours vs CEFR Levels · The ILR Scale Explained