The honest answer is "it depends": on how much you study, what you already speak, and what you mean by "learn". So set those below and get a real timeline. The base figures come from the U.S. Foreign Service Institute, which puts Indonesian at about 900 hours to professional proficiency (Category II).
Indonesian takes about 900 hours of study to reach professional working proficiency (about CEFR C1) for an English speaker, according to the U.S. Foreign Service Institute. That places it in FSI Category II; conversational B1 arrives far sooner. This calculator turns those hours into A1 to C1 milestones and adjusts for your native language and daily study time.
Time to hold a conversation (B1)
13 months
about 405 hours of study ยท Indonesian for English speakers
Estimates only. FSI hours are measured for native English speakers in intensive classroom study; the "for you" adjustment scales them by how close Indonesian is to your native language and script. Real timelines vary with method, motivation and exposure.
Whatever your timeline, you get there quicker by meeting Indonesian in real sentences, again and again. Lingo7 lets you read real books in Indonesian with tap-to-translate and native-narrated audio. Free to start.
The base figure is the FSI study-hour estimate: how many classroom hours the U.S. Foreign Service Institute found a native English speaker needs to reach professional working proficiency. Indonesian is Category II, about 900 hours. That number maps to roughly CEFR C1, so the earlier levels (A1 through B2) are scaled down from it using standard CEFR effort ratios.
When you pick a different native language, the total is adjusted for linguistic distance: a language in your own family branch and sharing your writing system transfers a lot and gets easier; an unrelated language with a different script gets harder. Then your daily study time turns those hours into calendar time, since the same hours spread over more minutes a day simply finish sooner.
It's an estimate, not a guarantee. What it's genuinely good at is showing that conversational Indonesian arrives much sooner than "fluent", and that steady daily contact, especially reading, is what moves the timeline.
Indonesian (Bahasa Indonesia) connects you with nearly 200 million speakers in the world's fourth most populous country, one of the largest economies in Southeast Asia, with a growing tech sector and vast cultural diversity.
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For an English speaker, the U.S. Foreign Service Institute estimates about 900 hours of study to reach professional working proficiency (roughly C1) in Indonesian, which is FSI Category II. At one hour a day that is 2 yr 6 mo; conversational level (B1) comes far sooner, around 13 months. Your own pace, native language and method shift the figure, which is why the calculator above lets you adjust them.
Conversational ability (CEFR B1) takes roughly 405 hours, about 13 months at an hour a day. At B1 you can handle everyday conversations, travel independently and follow the gist of simple authentic texts. Reading real Indonesian books with parallel translation gets you there faster because you meet useful words again and again in context.
Indonesian is FSI Category II, a moderately challenging tier for English speakers. Indonesian was deliberately designed as a simple lingua franca: it has no tones, no grammatical gender, no verb conjugation, no tenses, and uses a straightforward affixation system to derive words from roots. How hard it actually is depends heavily on the languages you already speak. A related language and shared script cut the time considerably, which the calculator reflects when you pick your native language.
Yes. The FSI hours assume classroom study; immersion and daily contact with the language compress the calendar time. The biggest levers are consistency (a little every day beats long gaps) and meeting the language in real context. Extensive reading with audio is one of the most efficient methods, because it builds vocabulary and grammatical intuition at scale.
Indonesian is FSI Category II (about 900 hours) and is often cited as one of the easiest Asian languages for English speakers. It has no tones, no verb conjugation, no grammatical gender, and uses the Latin alphabet. Reading Indonesian texts is accessible from early stages due to simple grammar and phonetic spelling.