Hardest AP® Classes: Compare Courses and Prerequisites

AP^® Physics C, Chemistry, and Calculus BC are usually the most demanding AP courses, because they build on substantial math or science background. Biology adds breadth and experimental reasoning, while courses such as U.S. History and English Literature require careful reading and evidence-based writing.

No single course is the hardest for everyone. What you have already studied, the assignments at your school, and the kind of work you enjoy can change the answer. If you're choosing classes for college, compare the best AP classes for your goals alongside this difficulty guide.

What makes an AP class hard?

Difficulty can come from advanced prerequisites, unfamiliar reasoning, the amount of material, or the time needed for assignments. A course that requires calculus presents a different challenge from one that requires sustained literary analysis.

The comparisons below are Fiveable's editorial assessment of published course skills and prerequisites, checked against College Board on August 31, 2026.

AP course	The main challenge	Preparation to check
Physics 1	Tying physical models, graphs, equations, and explanations together	Completed geometry; Algebra II can be concurrent
Biology	Applying biological concepts to experiments and data	High school biology and chemistry
Chemistry	Explaining lab evidence with particle models and calculations	High school chemistry and Algebra II
U.S. History	Using historical evidence in timed arguments	College-level reading and written explanations
Calculus BC	Working through AB's content plus series, parametric, and polar topics	Algebra, geometry, trigonometry, functions, and related precalculus topics
Physics C: Electricity and Magnetism	Using calculus to reason about fields and circuits	Calculus-based Newtonian physics; calculus taken or concurrent
Physics C: Mechanics	Calculus-based models of motion, forces, and energy	Calculus taken or concurrent
Calculus AB	Moving between limits, derivatives, and integrals	Algebra, geometry, trigonometry, and functions
English Literature	Interpreting prose and poetry and supporting an argument	College-level reading and writing
European History	Tracing historical developments and weighing sources	College-level reading and written explanations

The right-hand column combines College Board's course recommendations with skills worth raising with your teacher. Your school may also set its own enrollment rules, so ask which earlier courses it expects.

AP Physics 1

Physics 1 is algebra-based, but a familiar formula won't answer every question. You'll tie diagrams, graphs, calculations, and experimental evidence together to explain physical situations. College Board recommends completed geometry and concurrent enrollment in Algebra II or an equivalent course. Prior physics isn't listed as a recommended prerequisite. College Board's Physics 1 course overview

When practicing, start by drawing the situation and identifying the relevant relationship. If a graph shows velocity increasing, explain what that means for acceleration before calculating a value. This helps you check whether the equation fits the problem.

AP Biology

Biology covers processes at several scales, from cells to ecosystems. You'll need to apply concepts to data and experiments, and exam questions often ask how changing one variable affects a biological system. College Board recommends high school biology and chemistry. College Board's Biology course overview

Practice linking a claim to the specific evidence that supports it. For an enzyme experiment, describe the pattern in the results and connect it to enzyme activity. Repeating a definition without using the data leaves the main task unfinished.

AP Chemistry

Chemistry links what you can observe in a lab to models of atoms, ions, and molecules. Its calculations and explanations build on earlier chemistry and Algebra II, which College Board recommends before enrolling. College Board's Chemistry course overview

Check your fluency with moles, ratios, and balanced equations early. Then practice explaining a result with a particle-level model. Correct arithmetic and a correct explanation are separate skills, so give both time in your review.

AP U.S. History

APUSH asks you to explain historical developments and support arguments with evidence. No prior course is recommended for it. The work includes reading sources and building written arguments. College Board's U.S. History course overview

Its exam includes short answers, a document-based question, and a long essay. Practice turning a broad claim into a specific argument, then explaining how each example supports it. When using a document, consider who created it and why. U.S. History assessment

AP Calculus BC

Calculus BC includes AB content and additional work with topics such as parametric and polar functions, sequences, and series. Its college equivalent extends beyond the first calculus semester. College Board recommends preparation in algebra, geometry, trigonometry, functions, and related precalculus topics; it doesn't list AP Calculus AB as a required earlier course. College Board's Calculus BC course overview

More content can mean a faster pace, depending on your school's sequence. Ask whether BC starts after precalculus or after AB at your school. Before enrolling, check that you can manipulate functions and use trigonometric relationships without relearning them during each calculus problem.

AP Physics C: Electricity and Magnetism

E&M uses calculus to study electric and magnetic phenomena. College Board recommends a previous calculus-based Newtonian physics course, such as Physics C: Mechanics or its equivalent, plus completed or concurrent calculus. College Board's Physics C: E&M course overview

One good check is whether you can translate a physical situation into a mathematical model. As you study fields and circuits, draw the relevant quantities and directions before calculating. Keep track of what each variable represents.

AP Physics C: Mechanics

Mechanics applies calculus to topics such as motion, forces, energy, momentum, and rotation. College Board explicitly allows calculus to be taken at the same time, so you don't have to finish a full calculus course first. College Board's Physics C: Mechanics course overview

If you're taking both concurrently, ask the teachers how their sequences connect. Learning a calculus procedure shortly before using it in physics can require extra practice, but concurrent enrollment is an intended option.

AP Calculus AB

Calculus AB introduces limits, derivatives, and integrals. The challenge is relating those ideas across equations, graphs, tables, and written descriptions. College Board recommends preparation in algebra, geometry, trigonometry, and functions. College Board's Calculus AB course overview

When you miss a question, identify whether the difficulty was calculus or an earlier skill. Factoring errors need different practice from confusion about what a derivative measures. Bring a specific example to your teacher so you can address the gap.

AP English Literature and Composition

Literature asks you to explain how choices in prose, poetry, and drama create meaning. You don't need a prerequisite course, but the work requires close reading and analytical writing. College Board's Literature course overview

The exam includes poetry analysis, prose analysis, and literary argument essays. Practice moving from a textual detail to an interpretation: explain what a change in imagery suggests, then connect that observation to your claim. Use the published scoring guidelines to see what earns credit. Literature assessment

AP European History

European History combines a broad historical scope with source analysis and argument writing. You'll compare developments and explain causes and changes over time. College Board lists no recommended prerequisite. Reading sources and explaining historical claims are part of the course. College Board's European History course overview

Organize notes around relationships as well as dates. For a political change, ask what economic or social conditions contributed to it and whose position changed afterward. Those connections give you material for historical arguments.

Which science AP is hardest?

Compare the prerequisites first. Physics C: E&M recommends earlier calculus-based physics; Chemistry recommends chemistry and Algebra II; Biology recommends biology and chemistry. Physics 1 is algebra-based and has no recommended prior physics course.

Those are different starting points. If calculus is unfamiliar, Physics C may be a poor immediate fit. If you're comfortable with math but need practice interpreting experiments, Biology may require more adjustment than expected. Read the course tasks and ask about lab assignments before choosing.

Is Calculus BC harder than AB?

BC covers more calculus content, so there's more to learn. It includes AB topics plus additional techniques and topics such as infinite series. Whether your BC class moves faster depends on the school's sequence and whether you have already studied calculus.

Base your choice on what you've already studied and the local syllabus. The pass rates for the two courses reflect who signs up for each one, so they can't tell you which course is easier for you.

Why pass rates don't give you a difficulty ranking

College Board's AP score distributions show how exam takers scored in a given year. Different courses have different participants and prerequisites, so comparing their score rates isn't a controlled comparison of difficulty.

The same caution applies to estimated raw-score cutoffs. Your class grade, weekly workload, and eventual AP score answer different questions.

When you read someone else's ranking, check the date and what it measured. Course content, exam results, and survey answers give you three different pictures, and none of them predicts your experience in the class.

Should you take a challenging AP class?

Consider it when you're interested in the subject, have the background, and can make room for its work. Difficulty by itself doesn't establish a course's value. Yale's admissions guidance, for example, emphasizes challenging coursework across subjects, strong performance, and the opportunities available at your school. Yale's course-selection guidance

Individual colleges and programs weigh subjects differently, so a 5 in AP Physics doesn't automatically count for more than a 5 in AP Psychology. Use the best AP classes guide to compare course content against your interests, then check any subject requirements at the colleges you're considering.

You can also mix demanding courses with ones that use skills you already feel comfortable with. The easiest AP classes guide walks through those options course by course.

How to prepare without overloading your schedule

Ask for a syllabus and a typical assignment before you enroll. Compare lab reports, papers, projects, and test dates with the rest of your schedule. No single number of demanding AP courses works for every student.

Once the course starts, use a specific practice question to locate what needs work. Review the relevant concept, try a new question, and explain the answer without looking at the solution. For written work, compare your response with the rubric and revise the part that didn't meet it.

Browse Fiveable's AP subjects to preview course topics, then use AP practice or FRQ practice for the skills you're learning. A focused question for your teacher is a useful next step when a concept still doesn't make sense.