Language Learning Calculators

Study hours, vocabulary targets, review load and immersion planning. 9 calculators for self-directed learners. Formal schooling sits under Education.

Foreign Service Institute (FSI) difficulty draws on decades of United States State Department records: Spanish at 24 weeks, Japanese at 88. Read the conditions before planning around them. Those students are screened for language aptitude and study 25 hours a week with professional instructors. An adult fitting an hour a day around a job should expect two to three times the published figure, and there is nothing wrong with them for needing it.

Vocabulary coverage follows Paul Nation’s research, and the curve is steeper at the start and flatter later than most learners expect. A thousand words covers about 76% of an ordinary text, which is one unknown word in four and effectively unreadable. Five thousand reaches 95%, one in twenty, which is comfortable. Climbing from there to 98% takes another three thousand.

The spaced repetition pages assume you actually review daily. Skipping a week does not delay the load, it stacks it.

The Common European Framework of Reference (CEFR) hours page and the FSI page will give you different answers for the same language, and that is not a bug. One counts guided-learning hours against a European scale, the other counts weeks of full-time immersion against an American one.