CK-12: price, grades, and fit

CK-12 is a free online library from the CK-12 Foundation. The foundation’s info page says it is a non-profit organization that provides free educational materials and resources, and it calls Flexi a free digital tutor for every student. No tuition was printed, so the starting figure is $0. Free here means the published materials are not a tuition bill. A device, and any book you still choose to buy, can cost money. The subject menu labels science Grade K to 5. Elementary math links run from Grade 1 through Grade 5, then Math 6, Math 7, and Math 8. High school math on the same menu includes Algebra I, Geometry, Algebra II, probability and statistics, trigonometry, precalculus, and calculus. Biology, chemistry, physics, earth science, life science, and physical science are named. U.S. History and World History appear as community-contributed links, which the page says are created by users of the platform, so those two are not described here as foundation textbooks. College courses and an adult-education menu, including a High School Diploma heading, are on the page. Those headings were not opened, and college is not a matcher grade. No accreditor was named, so accreditation stays unknown. The student URL itself returned only a short title. A faith statement was not on the page, so faith stays not stated. The matcher uses kindergarten through grade 12 because science starts at K and the math menu continues through high school calculus. Not every subject starts at kindergarten. Lessons are on a screen. Our involvement estimate is medium. This is a library of materials, not a school that enrolls a child.

Where this listing sits

CK-12 is filed under free curricula. People also search CK-12, CK-12 Foundation, CK12. The directory name and the URL stay stable so an old link still lands here. CurriculumQuiz does not invent its own star score, run a parent poll, or sell a review. Third-party ratings quoted below stay in that section. Numeric ratings are combined into the independent average that orders program lists. That average is not a fact in the list above, and it is not a CurriculumQuiz score.

The price, read carefully

The official page presents CK-12 as free, so the starting figure is $0.00. Free means the published plan is not a tuition bill. It does not mean a year of homeschooling costs nothing. Books on a list, printing, supplies, and a device can still cost money. Source: official price page, checked October 29, 2026.

Grades

CK-12 is listed for Science is labeled Grade K to 5. Elementary math links run from Grade 1 through Grade 5, then Math 6, Math 7, and Math 8, plus high school math through calculus. College and adult-education headings are on the same menu and are not matcher grades.. In the quiz, that span is treated as grades 0 through grade 12. A program can still place a child by skill rather than age. Use the provider’s placement test when one exists, and do not force a level because of last year’s grade.

Accreditation and faith

Accreditation is unknown. We did not find a clear statement on October 29, 2026, so we did not guess. If you need a diploma from an accredited school, ask CK-12 directly or choose a listing where an accredited option is already recorded. Read the guide to accredited and non-accredited programs.

Faith stance: not stated. The page we checked did not clearly say secular, Christian, or Catholic. We will not assign one from reputation. If worldview matters in your house, read a sample chapter and the publisher’s own about page.

How the day is shaped

Free

Free, as a style tag, means the provider publishes materials without a tuition charge. You may still buy paper, a device, or the books on the list. For CK-12, the tag is a filing label from the official description, not a review of how your child will feel on a Thursday.

Online

Online delivery means the lesson is on a screen. It can cut preparation time. Younger children still need an adult nearby. For CK-12, the tag is a filing label from the official description, not a review of how your child will feel on a Thursday.

Self-paced delivery means the student can move without a live class on the calendar. Parent time is our estimate: medium. Someone is nearby to start the lesson, watch the frustration, and check that the work happened. You are not writing the curriculum from scratch, and you are not handing the whole day to a campus. This is an estimate from the program type. It is labeled as ours so you do not mistake it for a fact on the publisher’s price page.

Who it may suit

• You are willing to read the publisher’s own words about faith, because the page we checked did not state one.

Who may want a different listing

• You need an accredited diploma and this listing does not record one.

These notes come from the type, the style tags, and the faith and accreditation fields. They are not a quality review. A program can be a poor fit for your week and still be well made.

What the official site itself describes

Recorded from the official site on October 29, 2026: www.ck12.org returned a short page titled CK12-Foundation. The subject menu and the free-materials sentence are on https://info.ck12.org/. The menu includes a High School Diploma heading next to adult education. That heading was not opened as a diploma policy, and no accreditor was named. Some social-studies links, including U.S. History and World History, are labeled community-contributed content created by users of the platform. This sentence is a quotation of what we could verify. It is not a full catalog, and it is not a recommendation.

Questions to ask before you pay

• Does the price you were quoted include every subject, shipping, and a second child, or only the example on this page?
• Is there a placement test, and what happens if your child lands in a different level than their age?
• Who keeps grades and transcripts, you or CK-12? That answer matters for your state’s official rules.
• What is the refund or trial window, in the provider’s own words?
• On a normal Tuesday, how many minutes is a parent in the lesson?

What we are willing to leave blank

Still unknown after the October 29, 2026 check: accreditation, a stated faith stance. Unknown is a result. It is not a blank we fill in to make the table look finished.

How to use this page with the quiz

The curriculum quiz ranks CK-12 against the other 157 listings using your grade, style, time, budget, faith, accreditation need, and pace. Your state adds a link when we have an official source. It does not change the score. You can also put this program next to others in the compare tool. Families often look at AmblesideOnline, Core Knowledge, Discovery K12 in the same category. For the wider decision, read how to choose and the cost guide.

CurriculumQuiz is not affiliated with CK-12 unless an outbound link on this page is explicitly marked as an affiliate link. Today the affiliate field for this listing is empty, so the button goes to the official URL.