Where the 2 to 3 hours rule comes from
Many universities tell students to expect two to three hours of independent study for every hour of class. A 3-credit course therefore suggests 6 to 9 hours a week outside class. It is a planning guide, not a law, and the right number depends on the subject and on you.
Adjusting for difficulty and goals
This tool starts with the base figure and scales it for how hard you find the course and how high you want to score. A subject you already know needs less. A hard one that you want an A in needs more.
Making the hours count
Total hours matter less than how you spend them. Test yourself, space your revision and take breaks. The Pomodoro Focus Calculator can set out a session pattern, and the Exam Revision Calculator can spread topics across your weeks.
Frequently asked questions
How many hours should I study per credit?
A widely quoted guideline for US colleges is about 2 to 3 hours of study outside class per credit hour per week. It is a rule of thumb, not a requirement, and varies with the course, your background and your goals.
Does this work outside the US?
Yes, as an estimate. For a different credit system, such as ECTS, use the number of weekly class hours as the "credits" figure.
Is more study always better?
No. Quality matters more than hours. Active recall and spaced practice usually beat long passive sessions, and sleep and breaks are part of learning.
What if the total is more than I can do?
Then you may need to lower the target for some courses, drop a course, or find more hours. Better to see it now than during exams.