High School in the USA: Grades 9-12, Ages & Freshman to Senior Explained
Quick Answer: High school in the United States comprises grades 9, 10, 11, and 12. Students are typically between the ages of 14 and 18. Each grade level has a specific name: 9th grade (Freshman), 10th grade (Sophomore), 11th grade (Junior), and 12th grade (Senior).
High school represents the final four years of compulsory K-12 education in the US. It’s a critical time when students deepen their academic knowledge, explore extracurricular interests, and prepare for college or the workforce. This guide breaks down the structure, terminology, and typical ages for the American high school experience.
The Four Years of High School Explained
Each year of high school has a unique name and focus. For a more detailed breakdown of these terms and how they apply to college as well, check out our guide on Freshman, Sophomore, Junior, and Senior.
| Grade | Name | Typical Age | Focus |
|---|---|---|---|
| 9th Grade | Freshman Year | 14-15 | Transitioning to high school, adjusting to a new environment and higher academic expectations. |
| 10th Grade | Sophomore Year | 15-16 | Building a solid academic foundation and beginning to explore interests more deeply. |
| 11th Grade | Junior Year | 16-17 | Often the most academically rigorous year. Focus on standardized tests (SAT/ACT) and college preparation. |
| 12th Grade | Senior Year | 17-18 | Applying to colleges, scholarships, and enjoying the final year before graduation. |
The High School Curriculum and Graduation Requirements
To graduate, students must earn a specific number of credits by passing their courses. These requirements are set by the state and local school district but generally include a core set of subjects:
- English/Language Arts: 4 years
- Math: 3-4 years (often including Algebra I, Geometry, Algebra II)
- Science: 3-4 years (often including Biology, Chemistry, Physics)
- Social Studies/History: 3-4 years (including U.S. History, World History, Government)
- Physical Education: 1-2 years
- Electives: Courses in art, music, foreign languages, computer science, etc., to fulfill remaining credit requirements.
Advanced students can often take Honors, Advanced Placement (AP), or International Baccalaureate (IB) courses, which offer college-level curriculum and the chance to earn college credit. Calculating grades from these courses often requires understanding weighted vs. unweighted GPA.
Frequently Asked Questions (FAQ)
When do you start applying for college?
The college application process typically begins in the summer before and the fall of senior year (12th grade). However, preparation starts much earlier with standardized testing and building a strong academic record throughout high school.
How many high schools are there in the U.S.?
According to the National Center for Education Statistics (NCES), there are over 26,000 public secondary schools and over 12,000 private secondary schools in the United States. We explore this further in our article, How Many High Schools Are in the US?
How do I calculate when my child will graduate?
Our High School Entry Age & Graduation Year Calculator is the perfect tool for this. By entering your child’s date of birth, it can project their entire high school timeline, including their graduation year.
Last Updated: April 2025