Where the 120 hours comes from
The Carnegie unit dates back to the early 1900s. It describes one year of study in a subject: a class that meets four or five times a week, for 40 to 60 minutes, over 36 to 40 weeks. That works out to about 120 hours, and it is still how most U.S. high schools count credits.
Why many homeschool guides say 120 to 180 hours
Classroom hours include time that homeschoolers often don’t have (roll call, transitions), while homeschool hours often include reading and homework done independently. Many families count all the time spent on a subject and use 120 to 180 hours for a full credit. Lab sciences often land at the higher end because of lab time.
- Full credit (1.0): about 120–180 hours, usually a full school year.
- Half credit (0.5): about 60–90 hours, often one semester (for example Health or Government).
- Quarter credit (0.25): about 30–45 hours, a short unit or elective.
Other ways families decide on credits
Logging hours is one method. Another is completing a full high school level textbook or curriculum, which usually counts as one credit whatever the hours. Some families use mastery: the student demonstrated the skills a course covers. Whichever you use, apply it consistently and be ready to explain it in course descriptions.
How many credits to graduate?
Many public high schools require roughly 20 to 26 credits to graduate, and many homeschool families aim for something similar. College-prep plans often include about 4 credits of English, 3 to 4 each of math, science and social studies, and 2 or more of one world language. Requirements vary by state, umbrella school and college, so check the ones that apply to you.
Recording credits on the transcript
List each course with its credits (1.0, 0.5, 0.25 and so on), then total them per year and overall. TranscriptKit totals credits per year and per subject for you, and counts pass/fail courses toward credits.