If Indonesian is so simple, why is it 900 hours?

Because the simplicity is front-loaded and the difficulty is not. The first months are the easiest of any language here — you can build correct sentences almost immediately. What arrives later is a system of prefixes and suffixes that wrap around root words to change meaning and function, often in ways you cannot derive, and a spoken register that differs substantially from the formal one taught in courses. Neither is visible at the beginner stage, which is why Indonesian has a reputation for being easier than its hours suggest.

What is the affix system and why is it hard?

Indonesian builds vocabulary by attaching prefixes and suffixes, sometimes in combination, around a root — the same root generates verbs of several kinds, nouns, and abstractions. Learning the patterns is straightforward; the difficulty is that the resulting meaning is frequently idiomatic rather than predictable, so you cannot reliably generate the right derived word from a root you know. That makes it a vocabulary problem wearing a grammar problem\u2019s clothes, and it accumulates across the whole intermediate stage.

Is Indonesian the same as Malay?

They are two standardised forms of the same language, and mutual intelligibility is high — a speaker of one can converse with a speaker of the other with minor adjustment. The differences are in vocabulary, particularly in technical and administrative terms where Indonesian drew on Dutch and Malay on English, and in some everyday preferences and pronunciation. Our model treats them as very closely related, so learning either gives you most of the other.

How do you say things happened in the past?

With a separate word, or with nothing at all when context makes it clear. Indonesian verbs do not change form for tense, person or number, so "sudah" and similar markers do the job that verb endings do elsewhere, and they are omitted whenever the timeframe is already established. For an English speaker this is liberating at first and requires a genuine adjustment later: you have to trust context to carry information that English forces you to mark on every single verb.

How long does it take to learn Indonesian?

The US Foreign Service Institute reaches professional working proficiency in Indonesian in about 900 class hours — its middle band, between Spanish at 600 and Russian at 1,100. At an hour a day with a tutor, conversational Indonesian (B1) lands around 22 months. The beginning is genuinely the easiest of any language on this site: no tones, no cases, no gender, no conjugation, no plurals. The hours are spent later, on an affix system that reshapes root words and on a gap between formal Indonesian and the way people actually speak.

FSI baseline: 900 class hours
Difficulty band: moderate
FSI category: Category II / Category III

Indonesian sits in the Foreign Service Institute's middle band: 900 class hours to Speaking-3 / Reading-3 — between Spanish at 600 and Russian at 1,100, and the same figure as German.

The two standing warnings:

Those are classroom hours, not app minutes. Full-time small-group instruction with qualified teachers.

900 hours is professional proficiency — arguing a point in your field, reading a newspaper unaided.

The easiest beginning on this site

This deserves to be said plainly, because it is true and because it sets a trap.

Indonesian has no tones. No cases. No grammatical gender. No verb conjugation — a verb has one form regardless of tense, person or number. No plural marking as a requirement. No articles. The alphabet is Latin and the spelling is regular.

Word order is subject-verb-object. Tense is a separate word used when context does not already supply it, and omitted when it does.

A beginner produces correct Indonesian sentences within days. Nothing else here does that.

And FSI puts it at 900 hours, half again what Spanish costs. The gap between those two facts is the whole story of this language.

Where the time actually goes

Affixes, which behave like vocabulary

Indonesian builds words by wrapping prefixes and suffixes around a root. One root generates several verbs of different types, nouns, and abstract concepts.

The patterns themselves are learnable in an afternoon. The meanings frequently are not derivable. Knowing a root and knowing the affix pattern does not reliably tell you what the derived word means, because a large share of them are idiomatic.

So the affix system is a grammar-shaped surface over a vocabulary-shaped problem, and it has to be learned item by item across the entire intermediate stage. This is where the 900 hours mostly go, and it is invisible from the beginner's position.

The formal-versus-spoken gap

Formal Indonesian is the language of news, government and textbooks. Everyday conversation — especially in Jakarta — uses different pronouns, drops affixes the formal language requires, and borrows heavily from Javanese and English.

A learner working only from courses will read and write well before they can follow a casual conversation. That mismatch is common across languages and it is unusually wide here, because the formal register is a deliberately standardised construction.

Trusting context

Indonesian omits what context supplies: tense, number, sometimes the subject. For an English speaker this is liberating at first and requires real adjustment later, because English forces you to mark tense on every verb whether it matters or not.

Producing natural Indonesian means learning not to say things, which is harder to drill than learning to say them.

What each level actually costs

Goal	Method	Estimate
A2 — simple everyday exchanges	App, 20 min/day	around 450 hours, ~3.7 years
B1 — hold a conversation	Tutor, 1 hr/day, 5 days	around 473 hours, ~1.8 years
B2 — work, study, argue a point	Tutor, 1 hr/day, 5 days	around 690 hours, ~2.7 years
C1 — professional proficiency	Intensive class, FSI-style	900 hours, ~8 months full-time

Indonesian and Malay

Two standardised forms of the same language. Mutual intelligibility is high; a speaker of one converses with a speaker of the other after minor adjustment.

The differences are mainly vocabulary — Indonesian drew on Dutch for technical and administrative terms where Malay drew on English — plus everyday preferences and some pronunciation.

Learning either gives you most of the other, and our model treats the pair as very closely related.

What actually works

Do not let the easy start set your expectations. The first month is unrepresentative in a way that catches people out at month six.
Learn derived words as vocabulary, not as outputs of a rule. The rule tells you the shape; it does not tell you the meaning.
Get casual spoken Indonesian into your listening early. The formal register is what you will be taught and not what you will hear.
Practise leaving things out. Natural Indonesian omits what English insists on, and that is a habit rather than a piece of knowledge.

How you study matters more than which language

The same target, the same hour a day, five different ways of spending it.

Hours to B2 in Indonesian, holding everything else equal. The slowest method that gets there takes 2× the fastest — a wider gap than the one between neighbouring FSI difficulty bands. The hatched bar never arrives at all, however many hours go into it.

Run this for your own pace

Common questions

If Indonesian is so simple, why is it 900 hours?: Because the simplicity is front-loaded and the difficulty is not. The first months are the easiest of any language here — you can build correct sentences almost immediately. What arrives later is a system of prefixes and suffixes that wrap around root words to change meaning and function, often in ways you cannot derive, and a spoken register that differs substantially from the formal one taught in courses. Neither is visible at the beginner stage, which is why Indonesian has a reputation for being easier than its hours suggest.
What is the affix system and why is it hard?: Indonesian builds vocabulary by attaching prefixes and suffixes, sometimes in combination, around a root — the same root generates verbs of several kinds, nouns, and abstractions. Learning the patterns is straightforward; the difficulty is that the resulting meaning is frequently idiomatic rather than predictable, so you cannot reliably generate the right derived word from a root you know. That makes it a vocabulary problem wearing a grammar problem\u2019s clothes, and it accumulates across the whole intermediate stage.
Is spoken Indonesian different from what courses teach?: Yes, and it is one of the wider gaps on this site. Formal Indonesian is the language of news, official documents and textbooks. Everyday conversation, especially in Jakarta, uses different pronouns, drops affixes the formal language requires, and borrows heavily from Javanese and English. A learner who studies only the formal register will read and write well before they can follow a casual conversation, and the correction is unscripted audio rather than more coursework.
Is Indonesian the same as Malay?: They are two standardised forms of the same language, and mutual intelligibility is high — a speaker of one can converse with a speaker of the other with minor adjustment. The differences are in vocabulary, particularly in technical and administrative terms where Indonesian drew on Dutch and Malay on English, and in some everyday preferences and pronunciation. Our model treats them as very closely related, so learning either gives you most of the other.
How do you say things happened in the past?: With a separate word, or with nothing at all when context makes it clear. Indonesian verbs do not change form for tense, person or number, so "sudah" and similar markers do the job that verb endings do elsewhere, and they are omitted whenever the timeframe is already established. For an English speaker this is liberating at first and requires a genuine adjustment later: you have to trust context to carry information that English forces you to mark on every single verb.

Where to study Indonesian

Matched by the same rules the calculator uses, at a B1 target with no prior related language. The rules were written before any of these were added and the ranking code cannot read commission rates — a test rewrites every payout and checks the order does not move.

AnkiFree · Structured self-study course · up to C2earns us nothing
Anyone who needs to retain vocabulary — free, and better at spaced repetition than every paid app.
Not for: People who want a curriculum — Anki is a tool, not a course
Language ReactorFree · Structured self-study course · up to C1earns us nothing
Intermediate learners who want native input from video with dual subtitles, at no cost.
Not for: Beginners — unscripted native speech below A2 is noise, not input
Rocket Languagesabout $260 once · Structured self-study course · up to B2
Learners who want one structured course covering grammar explicitly, bought once rather than rented.
Not for: Anyone who wants live correction from a human — this is a recorded course
Pimsleurabout $150 once · Structured self-study course · up to B1
Learners who want to speak from the first lesson and can give it thirty focused minutes of audio a day, hands-free.
Not for: Anyone who wants to read or write the language — the method is almost entirely spoken

Your own target and budget change this list — run it for your case. Prices carry the date they were checked and go stale; confirm on the merchant's own site before paying.

Sources

Where the baseline figure on this page comes from. Everything applied on top of it is our own estimate.

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).
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.

By Kevin Fan. Native Mandarin speaker who learned English as a second language — the same pairing this site prices at 2,200 hours, done from the far side. Builds and maintains the estimate model and every page on it. Last reviewed 2026-08-08. How we work these numbers out, including which coefficients are our own estimates.