21. Henry M. Gunn High School
Henry M. Gunn High School in Palo Alto, California, has an average SAT score of 1410 and an average ACT score of 32. It has a student enrollment of 1,918 in grades 9-12. The student-teacher ratio is 19:1. Proficiency in mathematics is 91%, and proficiency in reading is 93%. The average graduation rate is 94%. This high school was founded in 1964, and it is in the top 25% of all California high schools by size.

It offers 22 Advanced Placement classes and eight honors classes that count for a weighted GPA. Every year, about 680 students at Gunn take 1,983 AP exams. High-quality teachers and classes prepare students thoroughly for their AP exams. Attending this school puts students in strong academic company. Gunn also hosts Project Lead the Way (PLTW), an organization that promotes math, science, technology and engineering. Courses include Introduction to Engineering Design, Principles of Engineering and Digital Electronics.

20. BASIS Oro Valley
BASIS in Oro Valley, Arizona, has an average SAT score of 1360 and an average ACT score of 31. It has a student enrollment of 537 in grades 6-12. The student-teacher ratio is 6:1. Proficiency in mathematics is 92%, and proficiency in reading is 88%. The average graduation rate is 90%. BASIS Oro Valley was one of the first charter schools to open, and it is consistently ranked as one of the top ten high school programs in the country. As a charter school, BASIS does not exclude students, but allows families to choose whether a student attends. Students start taking on a heavy load of AP classes in the 9th grade.

By senior year, they can participate in the Capstone program, taking seminar-style classes for two-thirds of the year. In their last trimester, they can propose an off-campus research project. The top-ranked liberal arts curriculum with a STEM focus inspires students to think critically, develop independence and formulate their own goals.

19. Union County Magnet High School
This school in Scotch Plains, New Jersey, has an average SAT score of 1370 and an average ACT score of 32. It has a student enrollment of 298 in grades 9-12. The student-teacher ratio is 13:1. Proficiency in mathematics is 95%, and proficiency in reading is 99%. The average graduation rate is 95%. This school is one of five Magnet high schools in the Union County Vocational-Technical School District. Students can take Advanced Placement courses and exams. The participation rate in these courses is 80%. Students are also prepared to become responsible, self-directed and productive individuals.

The engineering-based specialized academy emphasizes problem-solving, critical thinking and leadership skills through its project-based, rigorous curriculum. The goal is to provide students with the academic resources and latest technology to succeed in the modern world. The responsible use and application of technology helps to prepare them for the demands of college and beyond.