The High School Science Classes You Should Take


Which science classes are you required to take in high school, and what will you learn in them? Which science subjects will colleges expect you to have studied, and how can you impress them by exceeding these expectations?

Read this guide to learn about the standard science curriculum, what kinds of AP and IB science courses there are, college expectations, and how you can exceed colleges' expectations and use your high school science classes to ultimately strengthen your transcript.


What's the Standard High School Science Curriculum?

Most high schools require students to complete two to three years of science classes in order to graduate. These classes often include a laboratory component in which students must conduct hands-on experiments as part of the class.

The course sequence for science classes in most US high schools goes like this:

Biology → Chemistry → Physics

Some schools teach earth science during freshman year and then move on to biology and chemistry, whereas others follow the "Physics First" curriculum in which students take physics as freshmen.

The majority of high schools, however, follow the course sequence above and which we look at in more detail below.


Freshman Year: Biology

Biology is usually the first science high school students are taught because it has less of a focus on math than other science subjects do, giving freshmen time to hone their math skills before moving on to more math-focused sciences.

Main Topics:

  • Cells
  • The organism and its relationship to the environment
  • Human growth and development
  • Ecology
  • Genetics


Sophomore Year: Chemistry

Chemistry generally has greater emphasis on mathematical concepts and lab work than biology does, which is why it's typically taken sophomore year.

Main Topics:

  • Introduction to acids and bases
  • The mole concept
  • Reaction rates
  • Chemical energy


Junior Year: Physics or Earth/Physical Science

This is probably the first year that you'll have a choice in regard to which science subject to study: physics or earth/physical science.



Physics is most often taken by students who are more confident in their scientific and math abilities, who are planning to study science or math in the future, and/or who want to get into more competitive colleges. Physics frequently requires higher-level math skills (i.e., algebra and above).

Main Topics:

  • Concepts of time, space, and matter
  • Motion and forces
  • Optics and light
  • Electricity and magnetism
  • Atomic physics


Earth/Physical Science

Different schools might have different names for this course, but most classes cover topics from both earth and physical science. These classes are less math-intensive and often considered less rigorous than physics.

Main Topics in Earth Science:

  • Geology
  • Weather
  • Astronomy
  • Life processes

Main Topics in Physical Science:

  • Kinetics
  • Mechanics
  • Optics
  • Electricity
  • Magnetism


Should You Take Physics Over Earth/Physical Science?

It will look better on your transcript if you take physics, but most colleges don't require it unless you plan on majoring in math or science.

If you are applying to a highly competitive college, plan on studying math or science in the future, or are confident in your math and science abilities, then you should take physics.

If you struggle with math and science and aren't planning on majoring in either of those two fields, then it's probably fine to take earth/physical science instead of physics; however, you should try to take higher-level classes in other subjects, such as English or social studies, to keep your transcript strong.


Senior Year: Optional Electives

There is no standard science subject for high school seniors. Most high schools do not require seniors to take a science class, but if you choose to, you can take an elective. Electives are offered on a wide variety of subjects, including astronomy, human biology, and zoology.

Senior year is also an excellent year to strengthen your transcript by taking AP science classes (see "How to Exceed Colleges' Expectations" section below).



You'll have the opportunity to take a variety of science classes in high school. (Image Source: Pearson)


Which Science Classes Do Colleges Expect You to Have Taken?

Similar to high schools, most colleges require applicants to have taken two to three years of science. These requirements also often include passing both biology and chemistry.

However, if you're applying to a very selective college, be aware that many will require or highly recommend that you complete four years of science in high school. They might also require your fourth year of science to be an AP science class.

Regardless of the type of college you're interested in attending, if you plan to major in a STEM (Science, Technology, Engineering, and Math) field, you will be expected to have taken four years of science in high school, including physics.


How to Exceed Colleges' Expectations With Science Classes

If you're not planning on majoring in a STEM field or applying to highly competitive colleges, then it'll be more important for you to focus on courses that are more closely related to your intended major, rather than trying to exceed colleges' expectations with your science classes.

Colleges are more interested in how well you did in the subjects you plan to continue studying in college. Completing three years of science and getting solid grades in those classes is typically all you'll need to do in order to meet the expectations of college admissions officers.

However, if you're able to take four years of science classes, possibly with some of those classes at an honors or AP level, that's great and will strengthen your transcript. But don't pursue challenging science classes if it causes your grades in the area you plan to major in to drop.

If you intend to study a STEM field, it's important to show that you have strong science skills and that your science coursework goes beyond basic entrance requirements. You'll likely be using at least some of the skills you learn in your science classes in your future career, and colleges want to be sure you can handle the subject material before they admit you.

Also, since you'll be competing for a spot with many other talented STEM students, it's important to exceed expectations to help yourself stand out. You can accomplish this by taking four years of science, taking science courses at the highest level they're offered (honors or AP), and getting high grades in all those classes.

More specifically, here's what you should do if you're planning to major in a STEM field:

  • Take honors classes if possible your first three years
  • Take physics instead of earth science
  • Take one or more AP science classes your senior year
  • Get strong grades in all science classes you take

Below are several examples of advanced science classes you could take as a senior.


Science AP Classes

Here's a list of all AP science classes:

  • AP Biology
  • AP Chemistry
  • AP Physics C: Electricity and Magnetism
  • AP Physics C: Mechanics
  • AP Physics 1 and 2 (Algebra-Based)
  • AP Environmental Science
  • AP Computer Science A
  • AP Computer Science Principles

These classes expand on material learned in regular or honors-level science courses but are more rigorous, require more math skills, and often have a greater lab component.

If you plan on taking one or more of these classes your senior year, make sure you have enough room in your schedule. Because of the number of labs students must complete, these AP classes sometimes take one and a half or two class periods a day in order to fit in all the material.

Of the biology, chemistry, and physics AP classes, none is automatically the "best" to take; all are rigorous courses known for having challenging AP exams (although both Physics C tests are usually viewed as more difficult than Physics 1 and 2 because they require knowledge of calculus).

If you decide to take one of these courses, choose the one you think most relates to your future studies and career, or look at college websites to see which course(s) would earn you the most credits and make your decision that way.

AP Environmental Science is another option you have. This class focuses on human impacts on the environment, climate change, interrelationships of the natural world, and ways of developing solutions to environmental problems.

The difference is that AP Environmental Science isn't considered quite as rigorous as the other AP science classes because it usually doesn't have an honors prerequisite and requires less math and lab work; however, it's still an AP course and will therefore still be challenging and viewed more highly than if you were to take a non-AP science elective.

AP Environmental Science is a good option for someone who wants to take an AP science class but without as much rigor or time commitment, or for someone who is already taking a different AP science class and wants to add another that only takes up one class period.

Finally, you have two AP Computer Science classes to consider. These aren't exactly traditional sciences but are great options to think about, especially if you plan to major in computer science or a different computer- or technology-related discipline.

Whereas Computer Science A is more coding-heavy and technical, Computer Science Principles offers a broader overview of computing as a whole. Both tests are around the same difficulty level, with pass rates of about 70%.




Science IB Classes

In order to obtain the IB diploma, you must take at least one course from each of the six IB subject categories. Science is one of these categories, with seven different IB options available. Many IB courses are offered at both the Standard Level (SL) and Higher Level (HL).

The seven IB science courses are as follows:

  • Biology
  • Chemistry
  • Physics
  • Computer Science
  • Design Technology
  • Environmental Systems and Societies
  • Sports, Exercise, and Health Science


The 3 Main IB Science Courses: Biology, Chemistry, and Physics

These three classes are comparable to AP courses, although IB courses often include more report writing and lab work.

Particularly if you plan on studying science in college, it'd be a good idea to take one of these courses for the group requirement, as they're the science subjects colleges are most interested in.

All three courses are offered at SL and HL.


Computer Science

The Computer Science IB course focuses on computational thinking and how computers work. It also includes practical activities, such as programming. This class is a good option if you plan on studying computer science or a similar subject in college. It's offered at both SL and HL.


Design Technology

This course teaches students how to create solutions to common problems using the design cycle and technology. Some of the main subjects taught include modeling, sustainable production, and innovation and design. Like the IB courses above, Design Technology is offered at both SL and HL.


Environmental Systems and Societies

Environmental Systems and Societies is an interdisciplinary course that focuses on conservation and biodiversity, pollution management, and environmental demands of human populations. It's available at SL only.


Sports, Exercise, and Health Science

This IB science class focuses on human anatomy and physiology, as well as nutrition, psychology, and biomechanics. Students may take it at either SL or HL.



3 Additional Options for Science Classes

Whether you want to take a specific science class—perhaps one that is closely related to your future career—or simply want the opportunity to take more science classes beyond your high school's required curriculum, there are several ways you can do this.


Option 1: Electives

While taking an AP science class will look most impressive to colleges, electives are always an option as well, particularly if you don't plan on majoring in a STEM subject.

Many high schools offer a wide range of science electives, and these are a great way to take a class in a more specialized field of science you're particularly interested in, or to add more science courses to your transcript if you don't have the time or desire to take an AP science course.


Option 2: Community College Classes

If your high school doesn't offer a specific AP science class or elective, you might be able to take a similar course at a local community college. This is also a convenient way to take higher-level science classes that most high schools don't offer, such as advanced courses in biology, chemistry, or physics.

While taking a college-level class can be difficult, it'll look great on your transcript and you'll often get college credit for it. Talk to your guidance counselor to learn how to enroll in community college classes.


Option 3: Career-Focused Alternatives

It's becoming more common for high schools to offer classes that were developed specifically for students planning a science career, such as one in medicine or research.

My own high school, for example, offered a course for students who wanted to become doctors. Three days a week they would have a standard human physiology class, and twice a week they'd visit a local hospital and observe doctors and nurses.

Similar to job shadowing, taking these career-focused classes is a great opportunity to get more hands-on experience and see whether a particular career is right for you. Even if your school doesn't offer classes like this, you might be able to set up something similar as an independent study.



Your school might offer science classes specifically for students thinking about pursuing a degree in medicine.


Recap: What Science Classes Should You Take in High School?

Most colleges and high schools in the United States require you to complete two to three years of science classes. Most likely, you'll be required to take biology and chemistry your first two years of high school.

You should take physics your junior year if any of the following apply to you:

  • You are confident in your math and science abilities
  • You plan on majoring in math, engineering, or science in college
  • You are looking to attend a top college

If you plan on majoring in a STEM field, you should definitely take four years of science, including an AP science class your senior year, if possible.

If you will not be majoring in a STEM field, however, then you might want to consider taking science electives your senior year instead.


What's Next?

Trying to decide whether AP or IB is better for you? Check out our complete guide to see which program better aligns with your skills and goals.

Wondering which math classes you should take in high school, too? We've got an expert guide that goes over the standard curriculum, the basic course sequence, and the different ways you can impress colleges with your math class selections.

Considering summer academic programs for middle school and high school students? Take a look at our guides to the SIG, CTY, and Stanford EPGY programs to get started.



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About the Author
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Christine Sarikas

Christine graduated from Michigan State University with degrees in Environmental Biology and Geography and received her Master's from Duke University. In high school she scored in the 99th percentile on the SAT and was named a National Merit Finalist. She has taught English and biology in several countries.

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