FSI time-to-fluency estimator
An honest estimate of how long it will take you to reach a CEFR level in your target language, based on the US Foreign Service Institute's category data and your weekly study hours. The numbers below are guidance, not a guarantee; the variance comes mostly from how much real input (reading, listening) you do outside structured study.
Estimated time to reach B1:
13-20 months
Based on roughly 288-432 total study hours for a Category I language.
How this works
The Foreign Service Institute publishes broad ranges for how long it takes a native English speaker to reach "general professional proficiency" (roughly CEFR B2-C1) in each language category. Category I is closest (Spanish, French, Italian), Category V is furthest (Arabic, Mandarin, Japanese, Korean). This tool linearly scales the FSI hours range to your weekly study commitment and your target CEFR level.
The estimate is structural, not personal. Adult learners with more reading and listening practice hit each level faster than the FSI number; learners doing only an app finish later and plateau sooner.